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Human Anatomy and Physiology with Pathophysiology CHAPTER 1:THE HUMAN ORGANISMChapter 1: The Human Organism @medtech.files | by MAPB OUTLINE I.Anatomy II.Physiology III.Organization of the Human Body A.Chemical Level B.Cell Level C.Tissue Level D.Organ Level E.Organ System Level a.Major Organ System F.Organism Level IV.Characteristics of Life V.Homeostasis A.Negative Feedback B.Positive Feedback VI.Terminology and the Body PlanI. ANATOMY ‑investigates the structure of the body ‑to dissect, or cut apart and separate, the parts of the body for study Two approaches in studying: •Systemic anatomy-study of the body by systems •Regional anatomy-study of the body by areas Two ways to examine structures: •Surface anatomy-study of external features •Anatomical imaging-involves the use of technologies such as x-ray, ultrasound, MRI II. PHYSIOLOGY ‑deals with the process or functions of living things Goals: •To understand and predict the body’s responsesto stimuli •To understand how the body maintains internal conditions in the presence of continually changing internal and external environments III. SIX LEVELS OF ORGANIZATION OF THE BODY 1. Chemical Level ‑involves how atoms interact and combine into molecules B. Cell Level‑molecules combine to form organelles •Cells -basic structure and functional units of organisms •Organelles-small structures that make up some cells C. Tissue Level ‑group of similar cells and surrounding materials ‑four types: epithelial, connective, muscle, and nervous D. Organ level ‑composed of two or more tissue types that together perform one or more common functions E. Organ System Level ‑group of organs classified as unit because of a common function or set of functions F. Organism Level ‑organ systems make up an organism •organism-any living thing considered as a whole, whether composed of one cell, such as bacterium, or of trillions of cells, such as human Eleven Major Organ Systems: Integumentary System ‑provides protection, regulates temperature, prevents water loss, helps produce vitamin D ‑skin, hair, nails, sebaceous glands and sweat glands
Chapter 1: The Human Organism @medtech.files | by MAPB Skeletal System ‑provides protection and support, allows body movements, produces blood cells, and stores minerals and adipose tissue ‑bones, associated cartilages, ligaments, joints Muscular System ‑produces body movements, maintains posture, and produces body heat ‑muscles attached to the skeleton by tendons Nervous System ‑major regulatory system that detects sensations and controls movements, physiological processes, and intellectual functions ‑brain, spinal cord, nerves, sensory receptors Endocrine System ‑major regulatory system that influences metabolism, growth, reproduction, and many other functions ‑endocrine glands that secrete hormones Cardiovascular System ‑transports nutrients, waste products, gases, and hormones throughout the body; plays a role in the immune response and the regulation of body temperature ‑heart, blood vessels, and blood Lymphatic System ‑removes foreign substances from the blood and lymph, combats disease, maintains tissue fluid balance, and absorbs dietary fats from the digestive tract ‑lymphatic vessels, lymph nodes, other lymphatic organs Respiratory System ‑exchanges oxygen and carbon dioxide between the blood and air and regulates blood pH ‑lungs and respiratory passages Digestive System ‑performs the mechanical and chemical processes of digestion, absorption of nutrients, and elimination of wastes ‑mouth, esophagus, stomach, intestines, accessory organs Urinary System ‑removes waste products from the blood and regulates blood pH, ion balance, and water balance ‑kidneys, urinary bladder, and ureters Female Reproductive System ‑produces oocytes and is the site of fertilization and fetal development; produces milk for the newborn; produces hormones that influence sexual function and behaviors ‑ovaries, uterine tubes, uterus, vagina, mammary glands, and associated structures Male Reproductive System ‑produces and transfers sperm cells to the female and produces hormones that influence sexual functions and behaviors ‑testes, accessory structures, ducts, and penis IV. CHARACTERISTICS OF LIFE 1.Organization-specific relationship of the many individual parts of an organism 2.Metabolism-ability to use energy to perform vital functions, such as growth. Movement, and reproduction 3.Responsiveness-ability of an organism to sense changes in the environment and make the adjustments that help maintain its life 4.Growth-increase in size of all or part of the organism; it can result from an increase in cell number, cell size, or the amount of substance surrounding cells 5.Development-changes an organism undergoes through time •differentiation -change in cell structure and function from generalized to specialized •morphogenesis-the change in shape of tissues, organs, and the entire organism 6.Reproduction-formation of new cells or new organisms V. HOMEOSTASIS ‑maintenance of a relatively constant environment within the body ‑homeo-the same; stasis-to stop •Homeostasis mechanisms-maintain body temperature near set point (e.g., sweating or shivering) •variables-range of conditions that affect cell’s fluid•set point-average normal value A. Negative Feedback ‑to decrease ‑any deviation from the set point is made smaller or is resisted
Chapter 1: The Human Organism @medtech.files | by MAPB Three components ofnegative-feedback mechanisms: 1.Receptor-monitors the value of a variable by detecting stimuli 2.Control center-determines the set point for the variable and receives input from the receptor about the variable 3.Effector -change the value of the variable when directed by the control center Example: maintenance of normal body temperature B. Positive Feedback ‑to increase ‑occur when the initial stimulus further stimulates the response ‑at times, this type of response is required to re-achieve homeostasis VI. TERMINILOGY AND THE BODY PLAN Body PositionsAnatomical Position-a person standing upright with the face directed forward, upper limbs hanging to the sides, and palms facing forward •Supine -lying facing upward •Prone -lying facing downward Directional terms Directional Terms for the Human Body Term Etymology Definition Right Toward the body’s right sideLeft Toward the body’s left sideInferior Lower Below Superior Higher Above Anterior To go before Toward the front of the body Posterior Posterus, following Toward the back of the body Dorsal Dorsum, back Toward the back (synonymous with posterior) Ventral Venter, belly Toward the belly (synonymous with anterior) Proximal Proximus, nearest Closer to a point of attachment Distal di + sto,to be distant Farther from a point of attachment Lateral Latus, side Away from the midline of the body Medial Medialis, middle Toward the middle or midline of the body Superficial Superficialis, surface Toward or on the surface Deep Deop, deep Away from the surface, internal Body Parts and Regions A.Central region •Head •Neck •Trunk oThorax (chest) oAbdomen (belly) oPelvis (hips) B.Upper Limb •Arm -shoulder to elbow •Forearm -elbow to wrist •Wrist •Hand C.Lower Limb •Thigh -hip to knee •Leg -knee to ankle •Ankle •Foot
Chapter 1: The Human Organism @medtech.files | by MAPB Subdivisions of the Abdomen Four Quadrants Right Upper Quadrant •Liver, stomach, gallbladder, duodenum, right kidney, pancreas, transverse colon, right adrenal gland, small intestine Left Upper Quadrant •Liver, left adrenal gland, stomach, left kidney, pancreas, spleen, transverse colon, small intestine Right Lower Quadrant •Small intestine, large intestine, cecum, appendix, right ureter, right reproductive organs (ovary, fallopian tube, spermatic cord) Left Lower Quadrant •Small intestine, large intestine, left ureter, left reproductive organs (ovary, fallopian tube, spermatic cord, sigmoid colon) Nine RegionsRight hypochondriac •Liver, right kidney, small and large intestines Epigastric •Liver, stomach, duodenum, spleen, adrenal glands, pancreas Left hypochondriac •Liver’s tip, stomach, pancreas, left kidney, spleen, small and large intestines Right lumbar •Ascending colon, small intestine, and right kidney Umbilical •Duodenum, small intestine, and transverse colon Left lumbar •Descending colon, small intestine, left kidney Right iliac •Appendix, cecum, ascending colon, and small intestine Hypogastric •Bladder, sigmoid colon, small intestine, reproductive organs Planes •Sagittal plane -runs vertically through the body; separates right and left parts •Median plane or midsagittal -sagittal plane that passes through the midline; equal right and left •Transverse or horizontal plane -parallel to the surface of the ground; dividing superior and inferior •Frontal or coronal plane -vertically from right to left; dividing anterior and posterior abdominopelvic quadrants abdominopelvic regions
Chapter 1: The Human Organism @medtech.files | by MAPB •Longitudinal section -cut along the length of the organ•Transverse section -cross section; cuts completely through an organ•Oblique section -cut is made diagonally across the long axisBody Cavities •Thoracic cavity -surrounded by the rib cage; superior to muscular diaphragmoMediastinum-divides thoracic into left and right; houses the heart, thymus, trachea, and esophagus •Abdominal cavity -contains stomach, intestines, liver, spleen, pancreas, and kidneys; posterior to muscular diaphragm; bounded by abdominal muscles•Pelvic cavity -enclosed by pelvic bones; urinary bladder, part of large intestines, internal reproductive organs•Abdominopelvic cavity -abdominal and pelvic cavitiesSerous Membranes -line the trunk cavities and cover the organs of the cavities •Visceral serous membrane -inner wall; in contact with the organs•Parietal serous membrane -outer wall•Cavity or serous fluid -fills the space between the twoHeart •Pericardial cavity-surrounds the heart •Visceral pericardium-covers the heart •Parietal pericardium-outer layer of the sac around the heart •Pericardial fluid-fluid filling the pericardial cavity Lungs •Pleural cavity -surrounds each lung •Visceral pleura -covers each lung •Parietal pleura -lines inner surface of thoracic wall and lateral surface of mediastinum and superior surface of diaphragm •Pleural fluid -filling pleural cavity Abdominopelvic •Peritoneal cavity -serous membrane lined cavity in the abdominopelvic •Visceral peritoneum -covers many of the organs of abdominopelvic cavity •Parietal peritoneum -lines the wall of the abdominopelvic cavity and the inferior surface of diaphragm •Peritoneal fluid -filling the peritoneal cavity
Chapter 1: The Human Organism @medtech.files | by MAPB •Pericarditis -inflammation of the pericardium •Pleurisy -inflammation of the pleura •Peritonitis -inflammation of the peritoneum •Appendicitis -inflammation of appendix; rupturing will lead to peritonitis Mesenteries -two layers of peritoneum fused together; anchor the organs to the body wall; provide pathway for nerves and blood vessels Retroperitoneal -abdominopelvic organs that are closely attached to the body wall and do not have mesenteries; organs include kidneys, adrenal glands, portion of pancreas, parts of the intestines, and urinary bladder
Human Anatomy and Physiology with Pathophysiology CHAPTER 2: THE CHEMICAL BASIS OF LIFEChapter 2: The Chemical Basis of Life @medtech.files | by MAPB OUTLINE I.Basic Chemistry II.Chemical Reaction III.Acid and Bases IV.Inorganic Molecules A.Oxygen and Carbon Dioxide B.Water V.Organic Molecules A.Carbohydrates B.Lipids C.Proteins D.Nucleic Acids: DNA and RNA E.Adenosine Triphosphate I. BASIC CHEMISTRY Chemistry -concerned with the atomic composition and structure of substances and reactions they undergo A. Matter, Mass, and Weight •Matter-anything that occupies space and has mass •Mass-amount of matter in an object •Weight -gravitational force acting on object •Kilogram (kg) -international unit for mass B. Elements and Atoms •Element-the simplest type of matter having unique chemical properties •Atom-smallest particle of an element; contains protons, electrons, and neutrons C. Atomic Structure •Electrical charge -is the tendency of particles to be attracted to each other or repulsed from each other Three major types of subatomic particles: 1.Neutrons-do not have an electrical charge 2.Protons-positive charges 3.Electrons-negative charges •Nucleus -formed by protons and neutrons; located at the center of the atom where electrons move around; 99.97% of an atom’s mass•Electron cloud -region where electrons are most likely to be found •Atomic number-number of protons in each atom; also the number of electrons •Mass number-number of protons and neutrons in each atom D. Electrons and Chemical Bonding •Chemical Bonds -occur when outermost electrons (valence electrons) are transferred or shared between atoms •Electron shells -energy levels often drawn as concentric rings •Innermost shell-holds maximum of 2 electrons; closest to the nucleus •Valence shell-outmost shell •Octet -full valence shell •Octet rule-tendency of atoms to combine with other atoms until each has 8 electrons in its valence shell •Electronegativity -ability of nucleus to pull electrons toward it Types of Chemical Bonds Ionic Bond ‑occurs when there is an attraction between two oppositely charged ions •Ion -a charged atom formed because of a donation or gain of an electrons(s) Important Ions in the Human Body Ion Symbol Significance Calcium Ca2+Part of bones and teeth; functions in blood clotting, muscle contraction, release of neurotransmitters Sodium Na+ Membrane potentials, water balance Potassium K+Membrane potentials Hydrogen H+Acid-base balance Hydroxide OH- Acid-base balance Chloride Cl- Water balance Bicarbonate HCO3- Acid-base balance Ammonium NH4+Acid-base balance Phosphate PO43-Part of bones and teeth; functions in energy exchange, acid-base balance Iron Fe2+Red blood cell function Magnesium Mg2Necessary for enzymes Iodide I-Present in thyroid hormones Covalent Bond ‑occurs when atoms share one or more pairs of electrons •Molecule-resulting combination of atoms oSingle covalent bond -sharing of one pair of electrons by two atoms oDouble covalent bond -two atoms share two pairs of electrons
Chapter 2: The Chemical Basis of Life @medtech.files | by MAPB oPolar covalent bonds -forms when there is an unequal sharing of electrons; asymmetrical; results in a slightly positive charge (δ+)on one side of the molecule and a slightly negative charge (δ–) on the other side of the molecule. oNonpolar covalent bond -equal sharing of electrons; symmetrical; results in an even charge distribution among the atoms of the molecule E. Hydrogen Bond‑positive end of one polar molecule can be weakly attracted to the negative end of another polar molecule; weaker than ionic or covalent F. Molecules and Compounds •Molecule -two or more atoms chemically combine to form a structure that behaves as an independent unit •Compound -combination of two or more different types of atoms Picturing Molecules Representation Hydrogen Carbon Dioxide Chemical FormulaThe formula shows the kind and number of atoms present. H2 CO2 Electron-Dot FormulaThe bonding electrons are shown as dots between the symbols of the atoms. H:H O::C::O Bond-Line FormulaThe bonding electrons are shown as lines between the symbols of the atoms. H –H Single covalent bond O = C = O Double covalent bond ModelsAtoms are shown as different-sized and different-colored spheres. G. Dissociation •Dissociation -ionic compounds dissolve in water due to positively charged ions being attracted to negative ends of water molecules •Electrolytes-dissociated ions that have the capacity to conduct electrical current II. CHEMICAL REACTIONS ‑occur when there is a formation or breaking of chemical bonds between atoms, ions, molecules, or compounds •Reactants-substances that enter into the reaction •Products -substances that result from the reaction A. Classification of Chemical Reactions Synthesis Reaction ‑two or more reactants combine forming larger and more complex product ‑build a new molecule ‑energy-requiring A + B → ABExample: ADP + P → ATP•Anabolism-all synthesis reactions that occur in the body •Dehydration (water-out)-synthesis reaction in which water is also a product Decomposition Reaction ‑reactants are broken down into smaller and less complex products ‑energy-releasing AB → A + BExample: ATP → ADP + P•Catabolism-decomposition reactions that occur in the body •Hydrolysis (water breakdown)-reactions that uses water to breakdown reactants •Metabolism-all anabolic and catabolic reactions in the body Exchange Reaction ‑combination of synthesis and decomposition reactions AB + CD → AC + BDExample: HCl + NaOH → NaCl + H2OB. Reversible Reactions ‑occurs when the reaction can run in the opposite direction, so that the products are converted back to the original reactants CO2 + H2O = H++ HCO3
Chapter 2: The Chemical Basis of Life @medtech.files | by MAPB •Equilibrium -rates of product formation and reactant formation are equal; amount of the reactants relative to amount of the products remains constant C. Energy and Chemical Reactions •Energy -capacity to do work •Work -moving of matter •Kinetic energy-energy in motion •Potential energy-stored energy •Chemical energy-a form of potential energy stored in chemical bonds •Mechanical energy-energy resulting from position or movement of objects •Heat energy-energy that flows from a hotter object to a cooler object D. Rate of Chemical Reactions The rate at which a chemical reaction proceeds is influences by several factors: •Reactants -differ from one another in ability to undergo chemical reactions •Concentration of the reactants -the higher the concentration of reactants the faster the rate •Temperature-the higher the temperature, the faster the rate •Catalyst-increases of a reaction without itself being permanently changed or depleted III. ACIDS AND BASES Acid‑a proton H+donor; pH below 7 ‑Example: HCl in the stomach forms H+and Cl- Base ‑a proton H acceptor; pH above 7 ‑Example: NaOH forms Na+and OH-A. The pH Scale pH scale-measure of the H+ concentration of a solution •Neutral solution-equal number of H+ and OH-(=7) •Acidic solution -greater concentration of H+ than OH-(<7) •Basic or alkaline solution -fewer H+ than OH-(>7) Normal pH of blood: 7.35-7.45•Acidosis-pH blood below 7.35; depressed nervous system, individual becomes disoriented and possible comatose •Alkalosis-blood pH rises above 7.45; overexcitable nervous system, individual can be extremely nervous or have convulsions B. Salt‑compound consisting of positive ion other than H+and a negative ion other than OH-‑formed by the reaction of an acid and a base C. Buffers‑a chemical that resists changes in pH when either an acid or a base is added to a solution containing the buffer •The addition of an acid to a nonbuffered solution results in an increase of H+ and a decrease in pH •The addition of an acid to a buffered solution results in a much smaller change in pH. The added H+ bind to the buffer. IV. INORGANIC MOLECULES Inorganic chemistry-deals with substances that do not contain carbon
Chapter 2: The Chemical Basis of Life @medtech.files | by MAPB A. Oxygen and Carbon Dioxide •Oxygen (O2) -small, nonpolar, inorganic molecule consisting of two oxygen atoms bound together by a double covalent bond •Carbon dioxide (CO2) -consists of one carbon atom bound to two oxygen atoms; each oxygen atom is bound to carbon by double covalent bond B. Water •Water (H2O) -inorganic molecule consists of one oxygen joined by polar covalent to two hydrogen atoms oStabilizing body temperature oProviding protection oFacilitating chemical reactions oTransporting substances V. ORGANIC MOLECULES Organic chemistry-deals with carbon-containing substances Major Functional Groups of Organic Compounds Name and Structural Formula Functional Significance HydroxylR –O –H ‑Alcohols contain hydroxyl group ‑greatly increase the solubility of molecules in water SulfhydrylR –S –H ‑Thiols have a sulfhydryl group ‑can form a disulfide bond with another cysteine to help stabilize protein structure CarbonylO ║R –C –R ‑Ketones contain a carbonyl group within the carbon chain. ‑Aldehydes have the carbonyl group at the end of the carbon chain CarboxylO ║R –C –OH‑Carboxylic acids have a carboxyl group ‑All amino acids have a carboxyl group at one end EsterO ║R –C –O –R‑Esters are structures with an ester group ‑Triglycerides and dietary fats are esters. AminoHR –N H‑Amines have an amino group ‑All amino acids have an amine group at one end PhosphateO ║R –O –P –O-| O- ‑Phosphates have a phosphate group ‑used as an energy source (adenosine triphosphate), in biological membranes (phospholipids), and as intracellular signaling molecules (protein phosphorylation) A. Carbohydrates ‑contains C, H, O ‑H:O is a 2:1 ratio ‑building blocks: monosaccharidesFunctions: •Short term energy storage •Converted to glucose quickly •Glucose is used to make ATP (energy) •Brain cells require glucose Monosaccharides ‑simplest carbohydrates or simple sugar•Glucose (blood sugar) •Fructose (fruit sugar) •Galactose Disaccharide ‑formed by two monosaccharides joined by a covalent bond•Sucrose (table sugar) = glucose + fructose •Lactose (milk sugar) = glucose + galactose•Maltose (malt sugar) = glucose + glucosePolysaccharides ‑consists of many monosaccharides bound in long chains; starch, grain, vegetables, glycogen•Glycogen (animal starch) -used as energy source•Plant starch -broken down into cellulose•Cellulose -structural component of plant cell wallsB. Lipids ‑contains C, H, O (P, N in some) ‑contain a lower proportion of oxygen to carbon than to carbohydrates ‑building blocks: glycerol and fatty acids ‑provide energy (fats), serve as structural components (phospholipids), and regulate physiological processes (steroids) ‑Fats-important energy-storage molecules; pad and insulate the body ‑Triglycerides-most common type of fat molecules; 3 fatty acids bound to a glycerol Functions: •Long term energy storage •Insulates against heat loss •Protective cushion for organs •Cholesterol is part of a cell membrane Building blocks: 1.Glycerol -3-carbon molecules with hydroxyl group attached to each carbon
Chapter 2: The Chemical Basis of Life @medtech.files | by MAPB 2.Fatty acids-consist of carbon chain with carboxyl group attached to one end •Saturated fatty acid -single covalent bonds between atoms •Unsaturatedfatty acid-one or more double covalent bonds between carbons oMonounsaturated fats -have one covalent bond between carbon atomsoPolyunsaturated fats -have two or more double covalent bonds between carbon atoms•Trans fats -unsaturated fats that have been chemically altered by addition of H atoms •Phospholipids -composed of a polar region containing phosphate and a nonpolar region consisting of two fatty acid chains oHydrophilic -polar; water-loving; water-soluble oHydrophobic -nonpolar; water-fearing; water-insoluble •Eicosanoids -group of important chemicals derived from fatty acids; important regulatory molecules; role in response of tissues to injuries oProstaglandins -example of eicosanoids; implicated in regulating the secretion of some hormones, blood clotting, some reproductive functions, etc. •Steroids -composed of carbon atoms bound together into four ringlike structures •Cholesterol -other steroid molecules are synthesized from it; important component of cell membranes C. Proteins ‑contains C, H, O, N (S in most) ‑building blocks: amino acids•There are 20 basic types of amino acids (12 can be synthesize by humans; 8 must be obtained from diet) Functions: •Used to make skin, hair, nails, muscles •Part of the hemoglobin molecule •Act as enzymes •Immune system function •Muscle contractions (actin and myosin) •Part of cell membrane Protein denaturation -occurs when the hydrogen bonds that maintain shape of a protein are broken and the protein becomes a nonfunctional; caused by high temperatures and improper pHEnzymes-protein catalysts that increase the rate at which chemical reactions proceeds without the enzyme being permanently changed Activation energy -energy necessary to start chemical reaction D. Nucleic Acids: DNA and RNA ‑large molecules composed of C, H, O, N, P ‑building blocks: nucleotides•nucleotides -composed of a sugar (monosaccharide) to which a nitrogenous organic base and a phosphate group are attached Deoxyribonucleic acid (DNA) ‑genetic material of cells ‑transferred from one generation of cells to the next ‑contains genes which determine amino acid sequence and structure of proteins ‑adenine, thymine, cytosine, guanine ‑sugar: deoxyriboseRibonucleic acid (RNA) ‑exists in three forms that are important for protein synthesis ‑adenine, uracil, cytosine, guanine ‑sugar: riboseSingle ringed organic bases:thymine, cytosine, uracil Double ringed organic bases:adenine, guanine
Chapter 2: The Chemical Basis of Life @medtech.files | by MAPB E. Adenosine Triphosphate (ATP)‑essentially important organic molecule found in all living organisms ‑consists of adenosine (the sugar ribose with the organic base adenine) and three phosphate groups ‑energy currency of cells because it is capable of both storing and providing energy
Human Anatomy and Physiology with Pathophysiology CHAPTER 3:CELL STRUCTURES AND THEIR FUNCTIONSChapter 3: Cell Structures and Their Functions @medtech.files | by MAPB OUTLINE I.Cell Structure II.Functions of the Cell III.Cell Membrane IV.Movement Through the Cell Membrane A.Diffusion B.Osmosis C.Carrier-Mediated Transport Mechanisms D.Endocytosis and Exocytosis V.Organelles VI.Whole-Cell Activity A.Gene Expression B.Cell Cycle C.Differentiation D.Apoptosis VII.Cellular Aspects of Aging I. CELL STRUCTURE •Organelles-perform specific functions oNucleus-an organelle containing the cell’s material•Cytoplasm-living material surrounding the nucleus; contains many types of organelles •Cellmembrane-aka plasma membrane; encloses the cytoplasm II. FUNCTIONS OF THE CELL 1.Cell metabolism and energy use 2.Synthesis of molecules 3.Communication 4.Reproduction and inheritance III. CELL MEMBRANECell membrane/plasma membrane‑outermost component of a cell ‑encloses the cytoplasm ‑forms the boundary between inside and outside of cell •Extracellularsubstances-substances outside the cell •Intracellularsubstances-substances inside the cell ‑primarily made up of two major types of molecules: phospholipids and proteins ‑contains other molecules, such as cholesterol and carbohydrates Fluid-mosaic model•Hydrophilic head-polar, water-loving, phosphate containing •Hydrophobic tail-nonpolar, water-fearing, fatty acid ends •Cholesterol-adds strength and stability; limits amount of movement of phospholipid •Protein molecules-float among phospholipid molecules; extend from inner to outer surface •Carbohydrates-bound to some protein molecules, modifying their function Membrane proteins-function as membrane channels, carrier molecules, receptor molecules, enzymes or structural supports •Integral membrane proteins -penetrate deeply into the lipid bilayer; extending fromone surface to other •Peripheral membraneproteins-attached to either the inner or the outer surfaces of the lipid bilayer Membrane Protein Protein Function Marker MoleculesAllow cells to identify other cells or other molecules Attachment ProteinsAnchor cells to other cells (cadherins) or to extracellular molecules (integrins) Transport Proteins Channel ProteinsCarrier ProteinsForm passageways through the plasma membrane, allowing specific ions or molecules to enter or exit the cell; may be leak or gated Move ions or molecules across the membrane; binding of specific chemical to carrier proteins causes changes in the shape of the carrier proteins
Chapter 3: Cell Structures and Their Functions @medtech.files | by MAPB ATP-powered pumpsMove specific ions or molecules across the membrane; require ATP molecules to function Receptor ProteinsFunction as binding sites for chemical signals in the extracellular fluid; binding of chemical signals to receptors triggers cellular responses EnzymesCatalyze chemical reactions either inside or outside cells IV. MOVEMENT THROUGH THE CELL MEMBRANE Cell membranes are selectively permeable, meaning itallows some substances to pass into or out of cell membrane •Intracellular material -enzymes, glycogen, and potassium ions (K+) •Extracellular material-Na+, Ca2+, and ClActive membrane transportPassive membrane transportrequires energy (ATP)no energy required lower concentration to higher concentration higher concentration to lower concentration •active transport •secondary active transport •endocytosis •exocytosis •diffusion •osmosis •facilitated diffusion A. Diffusion ‑molecules tend to move from an area with higher concentration to lower concentration ‑results from the natural, constant random motion of all solutes in a solutionSolution-made up of solute and solvent •Solute-substances to be dissolved by solvent •Solvent-predominant liquid/gas in a solution Concentration gradient -difference in the concentration of a solute in a solvent between two points •Moves down (with CG) -solute diffuses from and area of higher concentration to lower •Moves up (against CG) -moves from an area of lower concentration to higher Diffusion Through the Cell Membrane Phospholipid bilayer -act as a barrier to most water-soluble substances Non-lipid-soluble molecules(red), such as ions, diffuse through membrane channels. Lipid-soluble molecules(orange), such as O2, CO2, and steroids, diffuse directly through the cell membrane. Leak and Gated Membrane Channels •Leak channels-constantly allows ions to pass through •Gated channels-limit the movement of ions by opening and closing In this example, the K+ leak channel(purple) is always open, allowing K+ to diffuse across the cell membrane. The gated Na+channel(pink) regulates the movement of Na+ across the membrane by opening and closing. Factors affecting rate of diffusion: 1.Temperature •the higher temperature, the faster the rate of diffusion 2.Molecular weight •the higher the molecular weight, the slower the rate of diffusion 3.Concentration difference/gradient B. Osmosis‑diffusion of water across a selectively permeable membrane from higher water concentration to lower water concentration
Chapter 3: Cell Structures and Their Functions @medtech.files | by MAPB •Osmotic pressure -force required to prevent the movement of water across a selective permeable membrane; measure of the tendency of water to move by osmosis •Hydrostatic pressure -moves the water out of the tube back into distilled water surrounding the tube ↑ concentration of solution, ↑ osmotic pressureHypotonic Isotonic Hypertonic Higher solute inside Equal solute Higher solute outside Higher water outside Equal water Higher water inside Water moves in No net movement Water moves out Cell swells Normal Cell shrinks Hypotonic solution ‑lower concentration of solutes, higher concentration of water relative to cytoplasm; less tonicity and osmotic pressure; water moves into the cell causing it to swell ‑lysis-the process of rupturing of cell caused by too much swelling Isotonic solution ‑concentration is same both sides of cell membrane; neither shrinks nor swells Hypertonic solution ‑higher concentration of solutes; lower concentration of water relative to cytoplasm; higher tonicity and osmotic pressure; water moves out of cell causing it to shrink ‑crenation-cell shrinkage C. Carrier-Mediated Transport Mechanisms ‑move larger water-soluble molecules or electrically charged ions across cell membrane ‑exhibit specificity (only specific molecules are transported by the carriers) Three Kinds of Carrier Mediated Transport Facilitated Diffusion ‑moves substances across the cell membrane from an area of higher concentration to lower concentration ‑movement is with the concentration gradient ‑ATP is not required ‑uses transport membrane Active Transport ‑moves substances across the cell membrane from lower concentration to higher ‑against concentration gradient ‑accumulate substances on the cell membrane; stops w/o ATP •Cystic fibrosis-genetic disorder that affects active transport of Cl-into ells •Sodium-potassium pump-example of exchanging one substance for another; moves Na+ out of cells and K+ into cells Secondary Active Transport ‑involves the active transport of one substance across the cell membrane, establishing a concentration gradient •Cotransport/Symport-diffusing substance moves in the same direction as the transported substance •Countertransport/Antiport-diffusing substance moves in a direction opposite to the transported substance D. Endocytosis and Exocytosis Vesicle-a membrane-bound sac where large water-soluble molecules can be transported Endocytosis‑uptake of material through the cell membrane by the formation of a vesicle ‑the cell membrane invaginates (folds inward) to form a vesicle •Receptor-mediated endocytosis-specific substance binds to the receptor molecule, endocytosis is triggered, and the substance is transported into the cell •Phagocytosis -cell-eating; solid particles are ingested •Pinocytosis -cell-drinking; smaller vesicles are formed Exocytosis ‑export of material ‑secretory vesicles move to the cell membrane, where the vesicle membrane fuses with the cell membrane, and the material in the vesicle is released from the cell ‑Secretory vesicles-accumulate materials for release from the cell Summary: Movement Across Membranes Types Transport ATP Diffusion With the concentration gradient through the lipid portion of the cell membrane or through membrane channels No Osmosis With the concentration gradient (for water) through the lipid portion of the cell membrane or through membrane channels No
Chapter 3: Cell Structures and Their Functions @medtech.files | by MAPB Facilitated diffusion With the concentration gradient by carrier molecules No Active transport Against the concentration gradient by carrier molecules Yes Secondary active transport Against the concentration gradient by carrier molecules; the energy for secondary active transport of one substance comes from the concentration gradient of another Yes Endocytosis Movement into cells by vesicles Yes Exocytosis Movement out of cells by vesicles Yes V. ORGANELLES Nucleus ‑contains genetic material of cell (DNA) and nucleoli; site of RNA synthesis and ribosomal subunit assembly; located at the near center of the cell•Nuclear envelope -bounds nucleus; consists of outer and inner membranes with space in between•Nuclear pore -connection between inner and outer membranes where materials can pass through•Chromosomes -consists of DNA and proteins; 23 pairs•Chromatin -loosely coiled chromosomes•Nucleoli -diffuse bodies with no surrounding membrane where subunits of ribosomes are formed•Ribosomal ribonucleic acid (rRNA) -produced within nucleolus; form large and small ribosomal subunits when joined by proteinsRibosomes ‑site of protein synthesis; may be attached to other organelles ‑free ribosomes -not attached to organelle Endoplasmic reticulum ‑series of membranes forming sacs and tubules •Rough ER -ribosomes attached; protein synthesis •Smooth ER -lacks ribosomes; lipid synthesis; participated in detoxification; stores calcium ions in skeletal muscle Golgi apparatus ‑also called Golgi complexor Golgi body ‑closely packed stacks of curse, membrane-bound sacs; collects, modifies, packages, and distributes proteins and lipids Secretory vesicles ‑pinch off from Golgi apparatus and move to cell membrane; contains materials produced in cell ‑Vesicles is a small, membrane-bound sac that transports or stores materials within cells Lysosomes and Peroxisomes •Lysosomes -formed from Golgi apparatus; contains enzymes that function as intracellular digestive systems •Peroxisomes -small, membrane-bound vesicles containing enzymes that break down fatty acids, amino acids, and hydrogen peroxide (H2O2) oHydrogen peroxide -by-product of fatty acid and amino acid; can be toxic to cell Mitochondria ‑small organelles with inner and outer membranes separated by a space ‑powerhouse of the cell; site of aerobic respiration; ATP synthesis •Cristae -numerous folds that projects into interior of mitochondria •Mitochondrial matrix -material within the inner membrane; contains enzyme and mitochondrial DNA (mtDNA) Cytoskeleton ‑internal framework of the cell; consist of protein structures that support the cell, hold organelles in place, and enable the cell to change shape •Microtubules -hollow structures formed from protein subunits; support the cytoplasm; assist in cell division; forming cilia and flagella •Microfilaments -small fibrils; support cytoplasm; determine cell shape; some are involved in cell movements; enable cell to shorten or contract •Intermediate filaments -smaller than microtubules but larger than microfilaments; mechanical support ; example is keratin (protein associated with skin cells)
Chapter 3: Cell Structures and Their Functions @medtech.files | by MAPB Centrioles ‑normally oriented perpendicular to each other; facilitate movement of chromosomes during cell division; each is composed of microtubules organized into nine triplets •Centrosome -close to the nucleus where microtubule formation occurs; contains 2 centrioles Cilia, Flagella, and Microvilli •Cilia -projects from the surface of cells; composed of microtubules; moves substances over surfaces of certain cells; transports mucus; keeps the lungs free from debris •Flagella -longer than cilia; usually occur only one per cell propel sperm cells •Microvilli -specialized extensions of the cell membrane that are supported by microfilaments; increase surface area of certain cells Summary: Organelles Organelles Location Functions Nucleus Often near center of the cell Contains genetic material of cell (DNA) and nucleoli; site of RNA synthesis and ribosomal subunit assembly Ribosomes In cytoplasm Site of protein synthesis Rough ER In cytoplasm Has many ribosomes attached; site of protein synthesis Smooth ER In cytoplasm Site of lipid synthesis; participates in detoxification Golgi apparatus In cytoplasm Modifies protein structure and packages proteins in secretory vesicles Secretory vesicle In cytoplasm Contains materials produced in the cell; formed by the Golgi apparatus; secreted by exocytosis Lysosome In cytoplasm Contains enzymes that digest material taken into the cell Peroxisome In cytoplasm Breaks down fatty acids, amino acids, and hydrogen peroxide Mitochondrion In cytoplasm Site of aerobic respiration and the major site of ATP synthesis Microtubule In cytoplasm Supports cytoplasm; assists in cell division and forms components of cilia and flagella Centrioles In cytoplasm Facilitate the movement of chromosomes during cell division Cilia On cell surface with many on each cell Move substances over surfaces of certain cells Flagella On sperm cell surface with one per cell Propel sperm cells Microvilli Extensions of cell surface with many on each cell Increase surface area of certain cells VI. WHOLE-CELL ACTIVITY A. Gene Expression ‑production of RNA and/or proteins from the information stored in DNA •DNA molecule -consists of nucleotides joined together to form two nucleotide strands •Gene -functional units of heredity; sequence of nucleotides that provides a chemical set of instructions •Heredity-transmission of genetic traits from parent to offspring Transcription‑first step in gene expression; takes place in the nucleus ‑synthesis of mRNA, tRNA, and rRNA molecules based on the nucleotide sequence in DNA •DNA: thymine, adenine, cytosine, guanine •RNA: uracil, adenine, cytosine, guanine •messenger RNA (mRNA) -copy of the gene produced; travels from the nucleus to the ribosomesoexons -regions of the mRNA that do code for proteinsointrons -regions that do not code for a protein•transfer RNA (tRNA) -carry amino acids to the ribosomes•codons -three nucleotide in a group that carries info in mRNATranslation ‑synthesis of a protein at the ribosome based on the sequence of the codons of mRNA; requires tRNA and ribosomal RNA (rRNA); ribosome binds to an mRNA and aligns it with tRNA ‑During translation, the sequence of codons in mRNA is used at ribosomes to produce proteins. Anticodons of tRNA bind to the codons of mRNA, and the amino acids carried by tRNA are joined to form a protein. •anticodon -three-nucleotide in tRNA that pairs with codon B. Cell Cycle Cell division-formation of daughter cells from single parent cell Meiosis-forms sex cells necessary for reproduction •Haploid-has half of the usual number of chromosomes (egg and sperm) Mitosis-division of parent cell to produce two daughter cells; forms new cells necessary for growth and tissue repair •Diploid-has paired chromosomes (23 pairs in human; 1 out of 23 is sex chromosome) •Autosomes-remaining 22 pairs of chromosomes
Chapter 3: Cell Structures and Their Functions @medtech.files | by MAPB Interphase‑nondividing phase; consume most of cell’s life; DNA is replicated ‑G1phase, S phase, and G2phase Mitosis 1. Prophase ‑chromatin condenses to form visible chromosomes; centrioles divide and migrate to each pole ‑in late prophase, nucleolus and nuclear envelope disappea •Chromatids -two genetically identical strands of chromatin •Centromere -specialized region where chromatids are linked •Spindle fibers -microtubules that extend from the centrioles; some attach to the centromeres of each chromosome2. Metaphase ‑chromosomes align near the center of cell (movements regulated by spindle fibers) 3. Anaphase ‑chromatids separate (each will be called chromosome); each of two sets of 46 chromosomes is moved to different pole of centriole by the spindle fibers ‑at the end, chromosomes reached opposite poles and cytoplasm begins to divide 4. Telophase ‑chromosomes become organized to form two separate nuclei for each daughter cell, begin to unravel and resemble genetic material during interphase Mitosis is complete, and a new interphase begins. The chromosomes have unraveled to become chromatin. Cell division has produced two daughter cells, each with DNA that is identical to the DNA of the parent cell. Cytokinesis ‑division of the cell’s cytoplasm to produce two new cells ‑begins in anaphase and continues through telophase ‑the first sign of cytokinesis is the formation of a cleavage furrow, an indentation of the plasma membrane that forms midway between the centrioles CLINICAL IMPACT •tumor-any abnormal mass of tissue that occurs within the body, usually involving cell proliferation •benign tumors-less dangerous; not inclined to spread, but they may increase in size •malignant tumors-can spread by local growth and expansion or by metastasis•cancer-refers to a malignant, spreading tumor and the illness that results from it
Chapter 3: Cell Structures and Their Functions @medtech.files | by MAPB C. Differentiation Differentiation -process which cells develop with specialized structures and functions; results from selective activation and inactivation of segments of DNA D. Apoptosis Apoptosis -programmed cell death; normal process by which cell numbers within tissues are adjusted and controlled; removes extra tissues in fetus Macrophages -specialize cells that phagocytize the cell fragments VII. CELLULAR ASPECTS OF AGING 1.Cellular clock -after certain passage of time or a certain number of cell divisions results in death of given cell line 2.Death genes-causing cells to deteriorate and die 3.DNA damage -DNA will be damaged through time resulting in degeneration and death 4.Free radicals -atoms and molecules with unpaired electrons which may damage the DNA directly resulting in mutation that may lead to cellular dysfunction and cell death 5.Mitochondrial damage -mitochondrial DNA may be more sensitive to free-radical damage that may result in loss of proteins
Human Anatomy and Physiology with Pathophysiology CHAPTER 4: TISSUESChapter 4: Tissues @medtech.files | by MAPB OUTLINE I.Tissues and Histology II.Epithelial Tissue A.Functions of Epithelia B.Classification of Epithelia C.Structural and Functional Relationships D.Glands III.Connective Tissue A.Functions of Connective Tissue B.Cells of Connective Tissue C.Extracellular Matrix D.Classification of Connective Tissue IV.Muscle Tissue V.Nervous Tissue VI.Tissue Membranes A.Mucous Membranes B.Serous Membranes C.Synovial Membranes VII.Tissue Damage and Inflammation VIII.Tissue Repair IX.Effects of Aging on Tissues I. TISSUES AND HISTOLOGY •Tissue-a group of specialized cells and the extracellular substances (matrix) surrounding them •Histology -microscopic study of tissue structure •Pathology -study of diseased tissues •Biopsy -removal of tissue from any part of the body •Autopsy-examination of organs of a dead body to know the cause of death or to study changes caused by a disease Four basic tissue types: •Epithelial •Connective •Muscular •Nervous Embryonic Tissue •endoderm-the inner layer, forms the lining of the digestive tract and its derivatives •mesoderm-the middle layer, forms tissues such as muscle, bone, and blood vessels •ectoderm-the outer layer, forms the skin oneuroectoderm-portion of the ectoderm that becomes the nervous system oneural crest cells-groups of cells that break away from the neuroectoderm during development; give rise to parts of the peripheral nerves, skin pigment, medulla of adrenal gland, many tissues of face II. EPITHELIAL TISSUE ‑also called epithelium ‑covers and protects surfaces, both outside and inside the body ‑protects by covering body structures or lining body spaces (internal and external) Characteristics: 1.Mostly composed of cells (cells close together with very little extracellular matrix) 2.Covers body surfaces 3.Distinct cell surfaces •Free or apical surface-where cells are exposed and not attached to other cells •Lateral surface -where cells are attached to other epithelial cells •Basal surface -attached to a basement membrane •Basement membrane -filter and barrier to cell movements; secreted by epithelial and connective tissue cells; helps attached the epithelial cells to the underlying tissues; supports and guide cell migration during tissue repair 4.Cell and matrix connections 5.Nonvascular (blood vessels in the underlying connective tissue do not penetrate the basement membrane) 6.Capable of regeneration A. Functions of Epithelia 1.Protecting underlying structures (ex: skin, epithelium of oral cavity) 2.Acting as a barrier (ex: skin keeps bacteria out) 3.Permitting the passage of substances (ex: lungs and kidneys) 4.Secreting substances (ex: sweat glands) 5.Absorbing substances (ex: small intestine)
Chapter 4: Tissues @medtech.files | by MAPB B. Classification of Epithelia Based on cell layers: •Simple epithelium-single layer of cells, with each cell extending from basement membrane to free surface •Stratified epithelium-more than one layer of cells, but only the basal layer attaches the deepest layer to the basement membrane •Pseudostratified columnar epithelium-appears to be stratified but consists of one layer of cells opseudo -false Based on cell shape: oSquamous-flat or scale like oCuboidal-cube-shaped; wide as they are tall oColumnar-tall and thin; taller than they are wide Classification of EpitheliumNumber of Layers Shape of Cells Simple(single layer of cells) Squamous Cuboidal Columnar Stratified(more than one layer of cells) Squamous Nonkeratinized (moist) Keratinized Cuboidal (very rare) Columnar (very rare) Pseudostratified(modification of simple epithelium) Columnar Transitional (modification of stratified epithelium) Roughly cuboidal to columnar when not stretched squamous-like when stretched Simple Epithelium Simple Squamous EpitheliumStructure:single layer of thin, flat cells often hexagonal cells; the nuclei appear as bumps when viewed in cross section Functions: diffusion, filtration, some secretion, and some protection against friction Location: lining of blood vessels and the heart, lymphatic vessels, alveoli of the lungs, portions of the kidney tubules, lining of serous membranes of body cavities (pleural, pericardial, peritoneal) Simple cuboidal epithelium Structure:single layer of cube-shaped cells; some cells have microvilli (kidney tubules) or cilia (terminal bronchioles of the lungs) •cilia-move mucus •microvilli-increase the surface area for secretion and absorption Functions:•secretion, excretion, absorption •carry out active transport, facilitated diffusion, or secretion •secretion and absorption by cells of the kidney tubules, glands, and choroid plexuses •movement of particles embedded in mucus out of the terminal bronchioles by ciliated cells Location: kidney tubules, glands andtheir ducts, choroid plexusesof the brain, lining of terminalbronchioles of the lungs, andsurfaces of the ovariesSimple Columnar Epithelium Structure:single layer of tall, narrow cells; some cells have cilia (bronchioles of lungs, auditory tubes, uterine tubes, uterus) or microvilli (intestines) •Mucus-a clear, thick fluid that protects the lining of the intestine Functions: •produces and secretes mucus and digestive enzymes (small intestine) •movement of particles out of bronchioles by ciliated cells •movement of oocytes through uterine tubes secretion by ciliated cells •secretion by cells of the glands, the stomach, and the intestines •absorption by cells of the intestines Location: glands and some ducts, bronchioles of lungs, auditory tubes, uterus, uterine tubes, stomach intestines, gallbladder, bile ducts, and ventricles of the brain
Chapter 4: Tissues @medtech.files | by MAPB Pseudostratified Columnar Epithelium Structure:single layer of cells; some cells are tall and thin and reach the free surface, and others do not; nuclei are at diff levels and appear stratified; almost always ciliated and associated with goblet cells •goblet cells-secrete mucus onto the free surface Functions: synthesize and secrete mucus onto the free surface and move mucus that contains foreign particles Location:lining of nasal cavity, nasal sinuses, auditory tubes, pharynx, trachea, and bronchi of lungs Stratified Epithelium Stratified Squamous EpitheliumStructure:several layers of cells that are cuboidal in the basal layer and progressively flattened toward the surface •nonkeratinized(moist) -surface cells retain a nucleus and cytoplasm •keratinized-surface is replaced by keratin and the cells are dead Functions: protects against abrasion, forms a barrier against infection, and reduce loss of water from the body Location: keratinized –outer layer of skin; nonkeratinized –mouth, throat, larynx, anus, vagina, inferior urethra, cornea Stratified Cuboidal EpitheliumStructure:more than one layer of cuboidal epithelial cells Functions: absorption, secretion, and protection Location: sweat gland ducts, ovarian follicular cells, salivary glands Stratified Columnar EpitheliumStructure:more than one layer of epithelial cells, but only the surface cells are columnar; deeper layers are irregular or cuboidal in shape Functions: secretion, protection, some absorption Location: mammary gland ducts, larynx, portion of male urethra Transitional EpitheliumStructure:stratified cells that appear cuboidalwhen the organ or tube is not stretched and squamouswhen stretched Functions: accommodates fluctuations in the volume of fluid in an organ/tube; protects against the caustic effects of urine Location: lining of urinary bladder, ureters, superior urethra Tissue not stretched
Chapter 4: Tissues @medtech.files | by MAPB C. Structural and Functional Relationships Cell Layers and Cell Shapes Cells are normally flat and thin when the function is diffusion. Cells with the major function of secretion or absorption are usually cuboidal or columnar. •Simple epitheliumis involved with diffusion, secretion, or absorption. •Stratified epitheliumserves a protective role. •Squamous cellsfunction in diffusion or filtration. •Cuboidal or columnar cells, which contain more organelles, secrete or absorb. Free Surfaces Free surfaces can be smooth or lined with microvilli or cilia. •Smooth free surface-reduces friction as material moves across it oendothelium -lining of blood vessels that is a specialized type of simple squamous; reduces friction as blood flows through the vessels •Microvilli -cylindrical extensions of the cell membrane that increase the free surface area •Cilia -propel materials along the free surface of cells; moves mucus Cell Connections 1.Mechanically bind the cells together 2.Help form a permeability barrier 3.Provide a mechanism for intercellular communication Desmosomes ‑mechanical links that bind cells together ‑contain plaque and have transmembrane glycoprotein (cadherins) that extend into the intracellular space between adjacent cells membranes and attach to one another Hemidesmosomes ‑modified desmosomes; anchor cells to the basement membrane ‑resemble desmosome but do not link adjacent cells ‑“half-desmosomes”‑transmembrane proteins: integrins Tight junctions ‑bind adjacent cells together and form permeability barriers ‑prevent the passage of material between epithelial cells Adhesion belt ‑found just below the tight junction ‑not as strong as desmosomes, they act as a weak glue that holds cells together Gap junctions ‑small channels that allow small molecules and ions to pass from epithelial cell to adjacent ‑connexin proteins which form tiny fluid filled tunnels called connexons that connect neighboring cells ‑allow intercellular communication D. Glands ‑secretory organs ‑composed primarily of epithelium, with a supporting network of connective tissue Exocrine glands‑glands with ducts; ex: sweat or oil glands Types of exocrine glands Based on the shapes of their ducts: •Simple -no branches; ex: intestinal glands•Compound -many branches; ex: mucous gland of oral cavityBased on their secretory units: •Tubular -end of duct; shaped as tubules (small tubes)•Alveolar/Acinar -sac-like structure•Tubuloacinar/Tubuloalveolar -combination of the two
Chapter 4: Tissues @medtech.files | by MAPB Based on type of secretion: Merocrine Secretion‑produce vesicles that contain secretory products ‑release through exocytosis ‑used by water-producing sweat glands and exocrine portion of pancreasApocrine Secretion ‑release of secretory products as pinched-off fragments of the gland cells ‑milk-producing mammary gland (combination of apocrine and merocrine) Holocrine Secretion ‑secretory products are stored in the cells of gland ‑involves the shedding of entire cells ‑used by sebaceous (oil) glands of the skin Endocrine glands‑no ducts (directly into bloodstream) ‑have extensive blood vessels ‑cellular products are called hormones(secreted into the bloodstream and carried throughout the body) ‑ex: thyroid, thymus, pituitary glands, etc. III. CONNECTIVE TISSUE ‑a diverse primary tissue type that makes up part of every organ in the body ‑cells far apart ‑contain large amounts of extracellular matrix A. Functions of Connective Tissue 1.Enclose and separate (Ex: around organs and muscles) 2.Connect tissues to one another •Tendons-connect bone to muscle •Ligaments-connect bone to bone 3.Support and movement (Ex: bones) 4.Storage (Ex. calcium and adipose tissue stores fat) 5.Cushion and insulating (Ex. Adipose tissue protects organs and helps conserve heat) 6.Transporting (Ex. Blood) 7.Protecting (Ex. Immune cells) B. Cells of Connective Tissue Suffixes that identify cell function: •-blast-cells build; create the matrix •-clast-cells that breakdown, remodel •-cyte-cells for maintenance Osteoblastsform bone, osteocytesmaintain it, and osteoclastsbreak it down. Fibroblastsare cells that form fibrous connective tissue and fibrocytesmaintain it. Chondroblastsform cartilage and chondrocytesmaintain it. Other cells: •Macrophages-large white blood cells capable of moving and ingesting foreign substances •Mastcells-nonmotile cells that release chemicals, such as histamine, that promote inflammation •Adipocytes-aka adipose cells, contain large amounts of lipid •WBC-aha leukocytes, increases dramatically in response to injury or infection •Platelets-fragments of hemopoietic cells that function in the clotting process to reduce bleeding from a wound •Undifferentiated mesenchymal cells-a type of adult stem cell that persist in connective tissue; have the potential to form multiple cell types C. Extracellular Matrix Three major components: (1) ground substance, (2) protein fibers, and (3) fluid (blood)
Chapter 4: Tissues @medtech.files | by MAPB Protein fibers Three types: •Collagen fibers-most abundant; look like ropes and are flexible but resist stretching oType I collagen-most abundant; found in tendons, ligaments, skin, and bone oType II collagen-found in cartilage oType III collagen-found in reticular fibers •Reticularfibers-very fine, short collagen fibers; support network that fills spaces between organs and tissues •Elastic fibers-have the ability to recoil after being stretched or compressed Ground substance ‑non fibrous proteins and sugars (proteoglycans) ‑shapeless background against which the collagen fibers are seen through microscope Two major components: •Hyaluronic acid-long, unbranched polysaccharide chain composed of repeating disaccharide units •Proteoglycans -large molecules that consists of a protein core attached to many long polysaccharides called glycosaminoglycansoChondroitin sulfate-common glycosaminoglycan oProteoglycan aggregate -trap large quantities of water allowing them to return to original shape when compressed or deformed oAdhesive molecules-hold the proteoglycan aggregates together and attach them to cells of tissue ‣Chondronectin-in ground substance of cartilage ‣Osteonectin-in ground substance of bone ‣Fibronectin-in ground substance of fibrous connective tissue D. Classification of Connective Tissues Embryonic Connective Tissue MesenchymeMucous Connective Tissue Adult Connective Tissue Connective Tissue Proper Loose (fewer fibers, more ground substance) Areolar Adipose Reticular Dense (more fibers, less ground substance) Dense, regular collagenous Dense, regular elastic Dense, irregular collagenous Dense, irregular elasticSupporting Connective Tissue Cartilage (semisolid matrix) Hyaline Fibrocartilage Elastic Bone (solid matrix) Spongy/Cancellous CompactFluid Connective Tissue Blood Red blood cells White blood cells Platelets Hemopoietic tissue Red marrow Yellow marrowEmbryonic Connective Tissue Mesenchyme Structure:mesenchymal cells are irregularly shaped; the extracellular matrix is abundant and contains scattered reticular fibers Location:mesenchyme is the embryonic tissue from which connective tissues, as well as other tissues, arise Mucous Connective Tissue Structure:mesenchymal tissue that remains unspecialized; the cells are irregularly shaped; the extracellular matrix is abundant and contains scattered reticular fibers Location:Umbilical cord of newborn
Chapter 4: Tissues @medtech.files | by MAPB CONNECTIVE TISSUE PROPER Loose Connective Tissue ‑Few protein fibers that form a lacy network, with numerous spaces filled with ground substance and fluid ‑Function: support and protect ‑Location: between organs, muscles, glands, skin Areolar Connective Tissue Structure:fine network of fibers (mostly collagen fibers with a few elastic fibers) with spaces between the fibers; fibroblasts, macrophages, and lymphocytes are located in the spaces Function: loose packing, support, and nourishment Location: widely distributed throughout the body; packing between glands, muscles, and nerves; attaches the skin to underlying tissue Adipose Tissue Structure:little extracellular matrix surrounding cells; the adipocytes are so full of lipid that the cytoplasm is pushed to the periphery of the cell Function: packing material, thermal insulator, energy storage, protection of organs Location:under the skin and around organs; subcutaneous areas, mesenteries, renal pelves, around kidneys, surface of colon, mammary gland Reticular Tissue Structure:fine network of reticular fibers irregularly arranged Function: provides a superstructure for lymphatic and hemopoietic tissues Location: lymph nodes, spleen, bone marrow Dense Connective Tissue‑large number of protein fibers that form thick bundles and fill nearly all of the extracellular space ‑collagen fibers packed close together •Dense regular-collagen fibers are oriented in same direction •Dense irregular-fibers are oriented in many different directions ‑Function: connect and can withstand pulling forces ‑Location: tendons, ligaments, skin Dense Regular Collagenous Connective Tissue Structure:matrix composed of collagen fibers running in same direction Function: withstand great pulling forces exerted in the direction of fiber orientation; great tensile strength and stretch resistance Location: tendons and ligaments Dense Regular Elastic Connective Tissue Structure:matrix composed of regularly arranged collagen fibers and elastic fibers Function: capable of stretching and recoiling like a rubber band with strength in the direction of fiber orientation Location: vocal folds and elastic ligaments between the vertebrae and along the dorsal aspect of the neck •Marfan syndrome -genetic condition results from the inability to properly maintain and form elastic fibers
Chapter 4: Tissues @medtech.files | by MAPB Dense Irregular Collagenous Connective Tissue Structure:matrix composed of collagen fibers that run in all directions or in alternating planes of fibers oriented in a somewhat single direction Function:tensile strength capable of withstanding stretching in all directions Location:sheaths; most of the dermis of the skin; organ capsules and septa; outer covering of body tubes Dense Irregular Elastic Connective Tissue Structure:matrix composed of bundles and sheets of collagenous and elastic fibers oriented in multiple directions Function:Capable of strength, with stretching and recoil in several directions Location:Elastic arteries SUPPORTING CONNECTIVE TISSUE Cartilage ‑composed of chondrocytesor cartilage cells, located in spaces called lacunae within an extensive matrix ‑contains collagen ‑withstand compressions ‑provides support, flexibility, strength ‑heal slowly Hyaline Cartilage Structure:collagen fibers are small and evenly dispersed in the matrix; covers the end of bones where they come together to form jointsFunctions: reduces friction (cushion); allows growth of long bones; provides rigidity with some flexibility Location: growing long bones, cartilage rings of respiratory system, costal cartilage of ribs, nasal cartilages Fibrocartilage Structure:more collagen than hyaline and are arranged in thick bundles Function: somewhat flexible and capable of withstanding compression; connects structures subjected to great pressure Location: between vertebra/knee; intervertebral disks, pubic symphysis, and articular disks Elastic Cartilage Structure:contains elastic fibers in addition to collagen and proteoglycans; elastic fibers appear as coiled fibers among bundles of collagen fibers; return to their original shape after being stretched Function: rigidity with even more flexibility than hyaline Location: external ears, epiglottis, auditory tubes
Chapter 4: Tissues @medtech.files | by MAPB Bone ‑hard connective tissue that consists of living cells and a mineralized matrix ‑Osteocytes-bone cells; located within lacunae ‑support and protect other tissues and organs Spongy bone/ Cancellous bone Structure:has spaces between trabeculae, or plates, of bone; resembles a sponge Function:acts as scaffolding to provide strength and support without the greater weight of compact bone Location:In the interior of the bones of the skull, vertebrae, sternum, and pelvis; in the ends of the long bones Compact bone Structure:hard, bony matrix predominates; many osteocytes are located within lacunae; matrix is organized into layers called lamellaeFunction: strength and support; protects internal organs such as brain; attachment site for muscles and ligaments; allows movements Location: Outer portions of all bones, the shafts of long bones FLUID CONNECTIVE TISSUE Blood ‑unique because the matrix is liquid, enabling blood cells and platelets, collectively called formed elements, to move through blood vessels Structure:Blood cells and a fluid matrix Function: transport oxygen, carbon dioxide, hormones, nutrients, waste products; protects the body from infections; temperature regulation Location: within blood vessels; WBC frequently leave blood vessels and enter extracellular spaces Bone Marrow Structure:Reticular framework with numerous blood-forming cells (red marrow) Function:Produces new blood cells (red marrow); stores lipids (yellow marrow) Location:Within marrow cavities of bone; red marrow–in the ends of long bones and in short, flat, and irregularly shaped bones; yellow marrow–in the shafts of long bones IV. MUSLE TISSUE ‑contracts, or shorten, making movement possible ‑muscle contraction results from contractile proteins located within the muscle cells •Muscle cells-excited by chemically, electrically and mechanically; sometimes called muscle fibers because they resemble tiny threads Skeletal Muscle Structure:long and cylindrical with many nuclei per cell (peripheral); striated(banded) Function: voluntarymovement of body Location: attached to bone or other connective tissue
Chapter 4: Tissues @medtech.files | by MAPB Cardiac Muscle Structure:cylindrical but shorter than skeletal muscle; striated; one nucleus per cell (centrally located); branched and connected to one another by intercalated disks, which contain gap junctions Function: pumps the blood; involuntary Location: heart Smooth Muscle Structure:not striated; single nucleus (centrally located); tapered at each endFunction: involuntary; regulates size of organs, forces fluid through tubes, controls the amount of light entering the eye; produces goose bumps; moving food through digestive tract and emptying the urinary bladder Location: hollow organs such as stomach and intestine; skin and eyes Summary: Muscle Types Skeletal Muscle Cardiac Muscle Smooth Muscle Attached to bones In the heart In the walls of hollow organs, blood vessels, eyes, glands, skin Very long, cylindrical cells Cylindrical cells that branch Spindle-shaped cells Multinucleated, peripherally located Single nucleus, centrally located Single nucleus, centrally located Striated Striated No striations Voluntary Involuntary Involuntary V. NERVOUS TISSUE ‑Function: transmit information in form of action potential; store information; glia support, protect and form specialized sheaths around axons ‑Location: brain, spinal cord, ganglia ‑responsible for coordinating and controlling many bodies activities ‑consists of neurons or nerve cells and neuroglial or glial cells Neurons ‑akanerve cells; responsible for conducting action potentials ‑action potentials-electrical signals Three parts: •Cell body -contains the nucleus; site of general functions•Dendrites -receive stimuli leading to electrical changes•Axon-conducts action potentials away from the cell bodyGrouped based on their structure: •Multipolarneurons-have multiple dendrites and a single axon •Bipolar neurons-have a single dendrite and an axon •Pseudo-unipolar neurons-have only a single, short process that extends from the cell body and then divides into two branches Glia ‑support cells of the nervous system; they nourish, protect, and insulate neurons VI. TISSUE MEMBRANES ‑a thin sheet or layer of tissue that covers a structure or lines a cavity •External membrane-cutaneous membrane •Internal membrane-mucous membrane, serous membrane, synovial membrane A. Mucous Membrane ‑consist of epithelium and thick layer of connective tissue ‑line cavities that open to the outside of the body (respiratory, digestive, reproductive system) ‑protection, absorption, secretion B. Serous Membrane ‑consist of simple squamous epithelium resting on layer of loose connective tissue ‑line the trunk cavities and cover the organs within the cavity
Chapter 4: Tissues @medtech.files | by MAPB ‑line cavities that do not open to the exterior of the body (pericardial, pleural, peritoneal cavities) ‑secrete a small amount of fluid called serous fluid, which lubricates the surface of membranes C. Synovial Membrane ‑made up of only connective tissue ‑line the cavities of freely movable joints ‑produce synovial fluid, which makes the joint very slippery VII. TISSUE DAMAGE AND INFLAMMATION Inflammation‑occurs when tissues are damaged ‑mobilizes the body’s defenses; destroys microorganisms, foreign materials, and damaged cells so tissue repair can proceed Five major symptoms: 1.Rubor(redness) -blood vessels dilate 2.Calor(heat) -due to increased blood flow 3.Tumor(swelling) -from water and proteins 4.Dolor(pain) -nerve ending are stimulated by damage and swelling 5.Functio laesa(loss of function) •Chemical mediators -released or activated in the injured tissue and adjacent blood vessles; cause dilation of blood vessels •Edema -swelling of tisse when water, proteins, and other liquid substances move into the tisses •Fibrin -forms a fibrous network that covers the site of the injury from the rest of the body; prevents the spread of infectious agents •Neutrophil -phagocytic WBC that absorbs bacteria which would die after absorbing it •Pus -mixture of dead neutrophils and other cell fluids Chronic inflammation ‑when the agent responsible for the injury is not removed or something blocks the process of healing VIII. TISSUE REPAIR ‑substitution of viable cells for dead cells ‑can occur by regeneration or by fibrosis Regeneration‑cells of same type develop (no scar); new cells are reproduced as the one’s that is destroyed, and normal function restores •Stem cells-self-renewing, undifferentiated cells that continue to divide throughout life Replacement/Fibrosis‑cells of a different type develop (scar); new type of tissue develops that eventually causes scar production and loss of tissue function Classification of cells according to their ability to regenerate: 1.Labile cells-continue to divide throughout life; damage to these cells can be repaired completely by regeneration 2.Stable cells-do not normally divide after growth cases, but they retain the ability to divide and are capable of regeneration in response to injury 3.Permanent cells-have a very limited ability to replicate and, if killed, are usually replaced by a different type of cell •Growth factors -a class of chemicals that stimulates stem cells to divide and make injured neurons recover more rapidly •Clot -contains the thread like protein fibrinthat binds the edges of the wound together that stops bleeding
Chapter 4: Tissues @medtech.files | by MAPB •Scab -seals the wound and helps prevent infection (forms 1 week after injury) •Macrophage -removes the dead neutrophils, cellular debris, and decomposing clot •Granular tissue-delicate granular-appearing connective tissue that consists of fibroblast, collagen and capillaries •Wound contracture -a result of the contraction of fibroblasts in the generation tissue that pulls the edges of the wound closer together IX. EFFECTS OF AGING ON TISSUES •Cells divide more slowly as people age. Injuries heal more slowly. •Extracellular matrix containing collagen and elastic fibers becomes less flexible and less elastic. Consequently, skin wrinkles, elasticity in arteries is reduced, and bones break more easily.
Human Anatomy and Physiology with Pathophysiology CHAPTER 5: INTEGUMENTARY SYSTEMChapter 5: Integumentary System @medtech.files | by MAPB OUTLINE I.Functions of the Integumentary System II.Skin A.Epidermis B.Dermis C.Skin Color III.Subcutaneous Tissue IV.Accessory Skin Structures A.Hair B.Glands C.Nails V.Physiology of the Integumentary System A.Protection B.Sensation C.Vitamin D Production D.Temperature Regulation E.Excretion VI.Integumentary System as a Diagnostic Aid VII.Burns VIII.Skin Cancer IX.Effects of Aging on the Integumentary System X.Diseases Integumentary system•consists of the skin and accessory structures, such as hair, glands, and nails. •Integumentmeans covering •Its appearance can indicate physiological imbalances in the body I. FUNCTIONS OF THE INTEGUMENTARY SYSTEM 1.Protection(from water loss, microbes, UV lights, abrasion) 2.Sensation(sensory receptors detects heat, cold, touch pressure, and pain) 3.Vitamin D production(when exposed to UV light, skin produces a molecule that transformed into vitamin D) 4.Temperature regulation(helps maintain homeostasis) 5.Excretion(removes waste through skin and gland secretions) II. SKIN Two major tissue layers of skin: •Epidermis -most superficial layer of skin; a layer of epithelial tissue that rests on the dermis; prevents water loss and resists abrasion•Dermis -a layer of dense connective tissue; average thickness is 10-20 times thicker than epidermis; responsible for most of skin’s structural strengthSubcutaneous tissue-aka hypodermis;a layer of connective tissue where skin rests; not part of the skin but connect skin to underlying muscle or bone A. Epidermis ‑a keratinized stratified squamous epithelium ‑in its deepest layers, new cells are produced by mitosis; as new cells form, old ones are pushed upwards and flake off Keratinization‑a process where cells change shape and chemical composition; new cells (with keratin) push old cells to surface ‑cells become filled with keratin ‑epithelial cell die and form an outer layer of dead, rigid cells ‑40-60 days for new cells to reach surface Cells of Epidermis: •keratinocytes-most cells of the epidermis •keratin-a protein that makes skin more rigid and durable •melanocytes-produce the pigment melanin •Langerhans cells -part of immune system •Merkel cells -specialized epidermal cells associated with the nerve endings responsible for detecting light touch and superficial pressure
Chapter 5: Integumentary System @medtech.files | by MAPB Strata-distinct layers that can be seen in epidermis 1. Stratum Corneum‑most superficial stratum of epidermis; outermost layer ‑composed of 25 or more layers of dead squamous cells joined by desmosomes ‑cornified cells-deadcells, with a hard protein envelope ‑accounts for 75% of epidermal thickness ‑provides protection to deeper tissues from mechanical injury, inward or outward diffusion ‑coated and surrounded by lipids, which act as waterproofing material, thereby preventing fluid loss •dandruff-excessive sloughing of stratum corneum cells from the surface of the scalp •callus-a thickened area that forms when stratum corneum has frequent friction •corn-thicken s. corneum to form a corn-shaped structure over a bony prominence 2. Stratum Lucidum ‑thin, clear zone above the stratum granulosum ‑translucent and allowing light to pass through ‑cells are dead and contain dispersed keratohyalin 3. Stratum Granulosum ‑two to five layers of flattened, diamond-shaped cells ‑the long axes of these cells are oriented parallel to the surface of the skin cells from protein granules ‑cells die •keratohyalin-protein granules which accumulate in the cytoplasm of the cell 4. Stratum Spinosum ‑8-10 layers of distorted (spined) cells ‑cells look spiny ‑as the cells in this stratum are pushed to the surface, they flatten; desmosomes break apart, and new desmosomes form ‑keratin fibers and lamellar bodies accumulate 5. Stratum Basale ‑deepest stratum ‑anchored to the basement membrane by hemidesmosomes‑consist of single layer of cuboidal or columnar cells that undergo mitotic divisions about every 19 days ‑takes approximately 40–56 days for the cell to reach the epidermal surface and slough off ‑where mitosis occurs Stratum Germinativum -between stratum spinosum and stratum basale Thick and Thin Skin Thick skin‑5 layers of epidermis; with stratum lucidum ‑no hair, subcutaneous glands and apocrine glands ‑found in areas subject to pressure or friction, such as palms of the hand, soles of the feet, and fingertips Thin skin‑4 layers of epidermis; absent stratum lucidum ‑covers the rest of the body and is more flexible than thick skin ‑thicker dermis ‑hair is found only in thin skin
Chapter 5: Integumentary System @medtech.files | by MAPB B. Dermis‑composed of dense collagenous connective tissue ‑contains collagen and elastic fibers ‑contains fibroblasts, adipocytes, macrophages, nerve ending, smooth muscle, blood vessels, and hair follicles •Collagen and elastic fibers-responsible for the structural strength of the dermis •Collagenfibersof the dermis are oriented in many different directions and can resist stretch •Cleavage lines or tension lines -produces by collagen fibers where skin is most resistant to stretch; due to orientation of collagen fibers; important in scarring •Stretch marks-produced when skin is overstretched and the dermis can be damaged, leaving lines that are visible through the epidermis; develop when a person increases in size quite rapidly 1. Papillary layer ‑loose connective tissue with thin fibers that are somewhat loosely arranged ‑contain many blood vessels that supplies the overlying epidermis with nutrients, removes waste products, and helps regulate body temperature ‑Dermal papillae -projections that extend toward the epidermis; shape the overlying epidermis into fingerprints and footprints 2. Reticular layer‑composed of dense irregular connective tissue ‑main layer of the dermis ‑deepest layer of dermis; accounts of 80% of dermis CLINICAL IMPACT Injections -introduce substances, such as medicines, to the body by puncturing the skin •Intradermal injection-drawing the skin taut and inserting a small needle at a shallow angle into the dermis; an example is the tuberculin skin test •Subcutaneous injection-pinching the skin to form a “tent” and inserting a short needle into the adipose tissue of the subcutaneous tissue; an example is an insulin injection •Intramuscular injection-inserting a long needle at a 90-degree angle to the skin into a muscle deep to the subcutaneous tissue; used for most vaccines and certain antibiotics C. Skin Color Factors that determines skin color include pigments, genetics, blood circulation, thickness of stratum corneum Melanin ‑group of pigments primarily responsible for skin, hair, and eye color ‑most molecules are brown to black pigments, but some are yellowish or reddish ‑provides protection against UV light from the sun ‑freckles are accumulation of melanin •Melanocytes-produces melanin; irregularly shaped cells with many long processes that extend between the epithelial cells of the deep part of the epidermis •Golgi apparatus-package melanin into vesicles called melanosomesMelanin Transfer to Keratinocytes 1.Melanosomes are produced by the Golgi apparatus of the melanocyte. 2.Melanosomes move into the melanocyte cell processes. 3.Epithelial cells phagocytize the tips of the melanocyte cell processes. 4.The melanosomes, which were produced inside the melanocytes, have been transferred to epithelial cells and are now inside them. Skin Color and Disease •Albinism - a recessive genetic trait that causes a deficiency or an absence of melanin. Albinoshave fair skin, white hair, and unpigmented irises in the eyes. •Erythema-skin turns a reddish hue when the amount of blood flowing through the skin increases; stimulated by infection, sunburn, allergic reactions, insect bites •Cyanosis- decrease in the blood O2content produces a bluish color of the skin •Birthmarks-congenital (present at birth) disorders of the blood vessels (capillaries) in the dermis •Carotene-a yellow pigment found in plants such as squash and carrots; source of vitamin A; lipid-soluble; accumulates in s. corneum •Hemoglobin-gives pinkish-red color •Suntan-exposure to ultraviolet light stimulates melanocytes to increase melanin production oMelanin builds up to help protect skin against UV radiation oSunburnis the skin reacting to UV exposure oUV light causes elastic fibers to clump and become leathery oUV light can alter DNA in cells causing them to mutate (cancer)
Chapter 5: Integumentary System @medtech.files | by MAPB III. SUBCUTANEOUS TISSUE ‑attaches the skin to underlying bone and muscle and supplies it with blood vessels and nerves ‑also called as hypodermis ‑below dermis ‑foundation of skin ‑loose connective tissue, including adipose tissue that contains about 1/2 of body’s fats‑can be used to estimate total body fat ‑body fat for females 20-23%, male 13-25% IV. ACCESSORY SKIN STRUCTURES A. Hair ‑found everywhere on the skin, except palms, soles, lips, nipples, parts of external genitalia, and distal segments of the fingers and toes •lanugo-unpigmented hair during fifth or sixth moth of fetal development •terminal hairs-pigmented hairs that replace the lanugo of the scalp, eyelids, and eyebrows •vellus hairs-short, fine, and usually unpigmented, replace the lanugo on the rest of the body Hair Structure •Shaft-protrudes above the surface of the skin •Root-located below the surface •Hair bulb-expanded base of the root where hair is produced •Cortex-surrounds the medulla •Medulla-soft center •Cuticle-covers the cortex; a single layer of overlapping cells that holds the hair in the hair follicle •Hair follicle-where hair arises; a tubelike invagination of the epidermis that extends deep into the dermis; group of cells that surround root and bulb •Hair papilla-an extension of the dermis that protrudes into the hair bulb •Arrector pili -smooth muscle cells; contraction of this muscle causes the hair to become more perpendicular to the skin’s surface; produces “goose bump”How is Hair Produced? •Hair is produces in hair bulb•Hair bulb rest on blood vessels to supply it with nutrients •Hair grows longer as cells are added to base of hair bulb Hair facts •Testosterone and good nutrition promote hair growth •Growth occurs in cycles: active and resting •Scalp hair grows for 3 years and rests for 1-2 year •Eyelashes grow for 30 days and rest for 105 gays •Loss of approximately 100 scalp hairs/day is normal •Grey hair is the loss or fading of melanin •Male pattern baldness is from the loss of the hair follicle B. Glands 1. Sebaceous Glands ‑simple, branched acinar glands ‑most are connected by a duct to the superficial part of a hair follicle ‑produces sebum •Sebum-an oily, white substance rich in lipids; released by holocrine secretion and lubricates the hair and the surface of skin, which prevents drying and protects against abrasion 2. Sweat/Sudoriferous Glands Eccrine sweat glands ‑simple, coiled, tubular glands and release sweat by merocrine secretion
Chapter 5: Integumentary System @medtech.files | by MAPB ‑located in almost every part of the skin but most numerous in the palms and soles ‑produce a secretion that is mostly water with a few salts. ‑have ducts that open onto the surface of the skin through sweat pores Apocrine sweat glands ‑are simple, coiled, tubular glands that produce a thick secretion rich in organic substances ‑are released primarily by merocrine secretion, though some glands demonstrate holocrine secretion ‑open into hair follicles, but only in the armpits and genitalia ‑become active at puberty because of the influence of sex hormones ‑think, rich secretions •Organic secretion-is essentially odorless when released, is quickly broken down by bacteria into substances responsible for what is commonly known as body odor Other Glands •Ceruminous glands-are modified eccrine sweat glands located in the ear canal oCerumen-aka earwax; combined secretions of ceruminous glands and sebaceous glands; protect the tympanic membrane by preventing dirt and small insects from moving too deeply •Mammary glands-are modified apocrine sweat glands located in the breasts; produce milk C. Nails ‑thin plate with layers of dead stratum corneum cells with hard keratin Nail Structure •Nail body-visual part •Nair root-covered by skin •Cuticle/Eponychium-stratum corneum that extends into nail body •Hyponychium -beneath the free edge of the nail body; a thickened region of the stratum corneum •Nail matrix -continuation of nail root; gives rises to most of nail •Nail bed-attached to nail and is distal to nail matrix •Lunula -part of nail matrix; whitish, crescent shaped area; base of nail V. PHYSIOLOGY OF THE INTEGUMENTARY SYSTEM A. Protection The skin reduces water loss, prevents the entry of microorganisms, and provides protection against abrasion and ultraviolet light; hair and nails also perform protective functions. B. Sensation The skin contains sensory receptors for pain, heat, cold, and pressure. C. Vitamin D Production 1.Vitamin D synthesis involves a precursor molecule, 7-dehydrocholesterol, which is stored in the skin. 2.When exposed to ultraviolet light, the precursor molecule is converted into cholecalciferol. 3.Cholecalciferol is released into the blood and modified first by the liver and later by the kidneys to form active vitamin D3, calcitriol. •Vitamin D can also be ingested through fish oils, fortified milk, eggs, and butter. •Vitamin D stimulates intestine to absorb calcium and phosphate (bone growth and muscle function)
Chapter 5: Integumentary System @medtech.files | by MAPB D. Temperature Regulation •Body temperature should be 98.6°F or 37°C •Rate of chemical reactions (metabolism) is altered by changes in temperature oTo cool body -blood vessels in dermis dilate and heat is transformed from deep in tissues to skin and sweat is produced oTo heat body -blood vessels constrict to reduce blood flow to skin and heat is retained E. Excretion Skin glands remove small amounts of waste products but are not important in excretion. VI. INTEGUMENTARY SYSTEM AS A DIAGNOSTIC ACID •Cyanosis-indication of impaired circulatory or respiratory function •Redness-fever, hypertension, inflammation, allergies •Pallor-pale; anemia or low blood pressure •Jaundice -yellowish skin that can indicate liver disorder •Bronzing -Addison’s disease (kidney disease)•Bruising -broken blood vessels VII. BURNS Burnis injury to a tissue caused by heat, cold, friction, chemicals, electricity, or radiation. Partial-thickness Burns First-degree burn ‑damages only epidermis ‑redness, slight edema or swelling, pain ‑heals within a week (usually no scar) ‑includes sunburns and exposure to hot or cold objects Second-degree burn ‑damages epidermis and upper dermis ‑redness, swelling, pain, blisters ‑heals in 2 weeks with some scarring Full-thickness Burn Third-degree burn ‑destroys epidermis and dermis ‑burned areas are cherry red to black ‑nerve endings are destroyed ‑skin graft might be necessary ‑usually painless because sensory receptors in the epidermis and dermis have been destroyed VIII. SKIN CANCER ‑most common cancer ‑mainly caused by UV light exposure ‑fair-skinned people are more prone ‑prevented by limiting sun exposure and using sunscreens ‑UVA rayscause tan and is associated with malignant melanomas ‑UVB rayscause sunburns ‑Sunscreens should block UVA and UVB rays Types of Skin Cancer Basal cell carcinoma ‑cells in stratum basale affected ‑cancer removed by surgery Squamous cell carcinoma ‑cells above stratum basale affected ‑can cause death Malignant melanoma ‑arises from melanocytes in a mole ‑appear as a large, flat, spreading lesion or as a deeply pigmented nodule ‑rare type ‑can cause death IX. EFFECTS OF AGING ON THE INTEGUMENTARY SYSTEM •Blood flow decreases and skin becomes thinner due to decreased amounts of collagen •Decreased activity of sebaceous and sweat glands make temperature regulation more difficult •Loss of elastic fibers cause skin to sag and wrinkle
Chapter 5: Integumentary System @medtech.files | by MAPB X. DISEASES Condition Description Birthmarks Congenital (present at birth) disorders of the dermal capillaries Ringworm Fungal infection that produces patchy scaling and inflammatory response in the skin Eczema and dermatitis Inflammatory conditions of the skin caused by allergy, infection, poor circulation, or exposure to chemical or environmental factors Psoriasis Chronic skin disease characterized by thicker than normal epidermal layer (stratum corneum) that sloughs to produce large, silvery scales Vitiligo Development of patches of white skin where melanocytes are destroyed, apparently by an autoimmune response Bacterial InfectionsImpetigoErysipelasDecubitus ulcers (bedsores, pressure sores)Acne Small blisters containing pus; easily rupture to form a thick, yellowish crust; usually affects children Swollen patches in the skin caused by the bacterium Streptococcus pyogenes Develop in people who are bedridden or confined to a wheelchair; reduced circulation result in destruction of skin and subcutaneous tissue, which later become infected by bacteria, forming ulcers Disorder of sebaceous glands and hair follicles that occurs when sloughed cells block the hair follicle, resulting in the formation of a lesion or pimple Viral InfectionsRubeola (measles)Rubella (German measles)ChickenpoxShinglesCold sores (fever blisters)Genital herpes Skin lesions; caused by a virus; may develop into pneumonia or infect the brain, causing damage Skin lesions; usually mild viral disease; may be dangerous if contracted during pregnancy because the virus can cross the placenta and damage the fetus Skin lesions; usually mild viral disease contracted through the respiratory tract Painful skin lesions; can recur when the dormant virus is activated by trauma, stress, or another illness; caused by the chicken pox virus after childhood infection Skin lesions; caused by herpes simplex I virus; transmitted by oral or respiratory routes; lesions recur Genital lesions; caused by herpes simplex II virus; transmitted by sexual contact
Human Anatomy and Physiology with Pathophysiology CHAPTER 6:SKELETAL SYSTEM: BONE AND JOINTSChapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB OUTLINE I.Functions of the Skeletal System II.Extracellular Matrix III.General Features of Bone A.Structure of a Long Bone B.Histology of Bone C.Bone Ossification D.Bone Growth E.Bone Remodeling F.Bone Repair IV.Bone and Calcium Homeostasis V.General Considerations of Bone Anatomy VI.Axial Skeleton A.Skull B.Auditory Ossicles C.Hyoid D.Vertebral Column E.Rib Cage VII.Appendicular SkeletonA.Pectoral Girdle B.Upper Limb C.Pelvic Girdle D.Lower Limb VIII.Joints IX.Effects of Aging on the Skeletal System and Joints X.Diseases Skeletal System •Rigid framework to support the soft tissues of the body and system of joints and levers to allow the body to move •Consists of bones, as well as their associated connective tissues including cartilage, tendons, ligaments •Joint or articulation-place where two bones come together I. FUNCTIONS OF THE SKELETAL SYSTEM 1.Support (provides framework; suited for bearing weight) 2.Protection (protects organs that it surrounds) 3.Movement (contraction of skeletal muscle pulls the tendons) 4.Storage (minerals such as calcium and phosphorus) 5.Blood cell production (red bone marrow produces RBC) II. EXTRACELLULAR MATRIX Components of Skeletal System •Bone •Cartilage-reduce friction and model for bone formation •Tendons-attach bone to muscle •Ligaments-attach bone to bone All are connective tissues Extracellular Matrix Matrix contains collagen, ground substance, organic molecules, water and minerals •Bone’s extracellular matrix -collagen and minerals flexible and able to bear weight •Cartilage’s extracellular matrix-collagen and proteoglycans (good shock absorber) •Tendons and ligaments’ extracellular matrix-collagen (very tough) Collagen-a tough ropelike protein Proteoglycans-large molecules that contains many polysaccharides attached to proteins; store water between polysaccharides Hydroxyapatite-calcium phosphate crystal in the bone Brittle bone disease-or osteogenesis imperfecta, imperfect bone formation; a rare disorder caused by faulty genes production that can result to little or poor-quality collagen formation or poor-quality collagen III. GENERAL FEATURES OF BONE Based on shape: •Long Bones-longer than wide and facilitate movement of appendages (ex: humerus, femur, tibia, etc.)
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB •Short Bones-approximately as wide as their long; helps the transfer of force between the long bones (ex: carpals and tarsals) •Flat Bones-relatively thin, flattened shape; well suited for providing a strong barrier around soft organs (ex: cranial bone, sternum, scapula, skull) •Irregular bones-complex in shape; bones that are not fit into the other three categories; provides protection while allowing bending and flexing of certain body regions (vertebrae and facial) A. Structure of a Long BonePart Description Diaphysis central shaft; compact bone tissue on the outside part Epiphysis two ends; spongy bone tissue; part of the bone that develops from a center of ossification distinct from the diaphysis Periosteum membrane around bone’s outer surface; consist of dense connective tissue Endosteum a thinner connective tissue that lines the medullary cavity Articular Cartilage thin layer of hyaline cartilage that covers the bone of the epiphyses where bone articulates with other bones Epiphyseal plate (growth plate)site of growth; between diaphysis and epiphysis; only present when the long bone is still growing; when a bone stops growing it is replaced by the epiphyseal line Spongy bone bone having many small spaces; found mainly in the epiphysis; arranged into trabeculae Compact bone dense bone with few internal spaces organized into osteons; forms the diaphysis and covers the spongy bone of the epiphyses Medullary cavity center of the diaphysis; red or yellow marrow Yellow marrow fat stored within the medullary cavity or in the spaces of spongy bone Red marrow blood forming cells; site of blood formation in adults Hematopoietic Tissue‑tissue that makes blood cells •Red marrow-location of blood forming cells •Yellow marrow-mostly fat ‑Location: •In newborns -most bones (red marrow) •In adults -red is replaced with yellow marrow; red marrow is mainly in epiphyses of femur and humerus B. Histology of Bone Bone Cells •Osteocytes-maintain bone matrix; osteoblasts surrounded matrix•Osteoblast-build bone; formation of the bones and repair and remodeling of the bone; found in periosteum an endosteum •Osteoclast-carve bone; present and contribute to bone repair and remodeling by removing existing bone called “bone reabsorption”Bone tissue found throughout the skeleton is divided into two major types, based on the histological structure: Compact Bone ‑also known as cortical bone‑Location: outer part of diaphysis (long bones) and thinner surfaces of other bones
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB •Osteon/Haversian system-structural unit of compact bone; includes lamella, lacunae, canaliculus, central canal, osteocytes •Lamella-rings of bone matrix; thin sheets •Lacunae-spaces between lamella where osteocytes are located •Canaliculus-tiny canals where cells process extends from the osteocytes; transport nutrients and remove waste •Central canal-aka Haversian canal; center of osteon; contains blood vessels Spongy Bone Tissue ‑cancellous bone ‑no osteons ‑Location: epiphyses of long bones and center of other bones •Trabeculae-interconnecting rods, spaces contain marrow C. Bone Ossification •Ossification-process of bone formation (occurs in utero) •Osteoblast’s role: build bone; after an osteoblast becomes surrounded by bone matrix it becomes an osteocyte•Ossification center-where bone formation begins oPrimary ossification center-where bone first begins to appear; forms diaphysis oSecondary ossification center-forms epiphyses Intramembranous Ossification‑bone formation within connective tissue membranes; osteoblasts build bone (ex: skull bone) ‑occurs in a 12-week-old fetus at ossification centers in the flat bones of the skull Steps: 1.Embryonic mesenchyme forms a collagen membrane containing osteochondral progenitor cells. 2.Embryonic mesenchyme forms the periosteum, which contains osteoblasts. 3.Osteochondral progenitor cells become osteoblasts at centers of ossification; internally, the osteoblasts form spongy bone; externally, the periosteal osteoblasts form compact bone. 4.Intramembranous bone is remodeled and becomes indistinguishable from endochondral bone. Endochondral Ossification‑bone formation inside cartilage; cartilage models are replaced by bone (ex: all bones except skull) Steps: 1.Embryonic mesenchymal cells become chondroblasts, which produce a cartilage model surrounded by the perichondrium. 2.Chondrocytes hypertrophy, the cartilage matrix becomes calcified, and the chondrocytes die. 3.The perichondrium becomes the periosteum when osteochondral progenitor cells within the periosteum become osteoblasts. 4.Blood vessels and osteoblasts from the periosteum invade the calcified cartilage template; internally, these osteoblasts form spongy bone at primary ossification centers (and later at secondary ossification centers) externally, the periosteal osteoblasts form compact bone. 5.Endochondral bone is remodeled and becomes indistinguishable from intramembranous bone. Timetable of Human Ossification Time PeriodBones AffectedThird month of embryonic development Ossification in long bones beginning Fourth month Most primary ossification centers have appeared in the diaphysis of bone Birth to 5 years Secondary ossification centers appear in the epiphyses 5-12 years in females, 5-14 years in males Ossification is spreading rapidly from the ossification centers and various bones are becoming ossified 17 to 20 years Bone of upper limbs and scapulae becoming completely ossified
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB 18 to 23 years Bones of the lower limbs and of coxas become completely ossified 23 to 25 years Bone of the sternum, clavicles and vertebrae become completely ossified By 25 years Nearly all bones are completely ossified D. Bone Growth Infancy and youth: •Long bones lengthen and epiphyseal late •Long bones widen by adding more lamella Appositional growth-increase in bone width and diameter End of bone growth (in length): epiphyseal plate is replaces by an epiphyseal line E. Bone Remodeling ‑removal of existing bone by osteoclasts and deposition of new bone by osteoblasts ‑occurs in all bones ‑responsible for changes in bone shape, bone repair, adjustment of bone to stress, and calcium ion regulation F. Bone Repair 1.Broken bone causes bleeding and a blood clot forms. 2.Callus forms which is a fibrous network between 2 fragment. •internal callus-forms between the ends of the broken bone, as well as in the marrow cavity if the fracture occurs in the diaphysis of a long bone •external callus-forms a collar around the opposing ends of the bone fragments 3.Cartilage model forms first then, osteoblasts enter the callus and from cancellous bone this continues for 4-6 weeks after injury. 4.Cancellous bone is slowly remodeled to form compact and cancellous bone. Classification of Bone Fracture According to the severity of the injury to the soft tissues: •Open fracture -formerly called a compound fracture; wound extends to the site of the fractures or a fragment of bone protrudes through the skin•Closed fracture -formerly called a simple fracture; skin is not perforated; damaged is only in the inside•Complicated fracture -when soft tissues around a closed fracture are damagedOther types of bone fractures: •Incomplete fracture-does not extend completely in the bone; sliced ogreen stick fracture-incomplete fracture on the convex side of the curve of the bone; bends and cracks ohairline fracture-incomplete fractures which two sections of the bone do not separate; common in skull; small crack or severe bruise •Complete fracture-broken into two pieces ocommunicated fracture-complete fracture in which the bone breaks into more than two pieces; usually two major and smaller fragments •Impacted fracture-a piece is driven into the spongy portion According to the direction of the fracture: •Linear fractures-run parallel to the length of the bone •Transverse fractures-right angles to the length of the bone •Spiral fractures-take a helical course around the bone •Oblique fractures-run obliquely in the relation to the length of the bone •Dentate fractures-have rough, toothed, broken ends •Stellate fractures-have breakage lines radiating from a central point
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB IV. BONE AND CALCIUM HOMEOSTASIS •Boneis a major storage site for calcium •Movement of calcium in and out of bone helps determine blood levels of calcium •Calcium moves into bone as osteoblasts build new bone •Calcium moves out of bone as osteoclasts break down bone Calcium homeostasisis maintained by three hormones: •parathyroid hormone (PTH)from parathyroid glands •vitamin Dfrom the skin or diet •calcitoninfrom the thyroid gland PTHand Vitamin Draise blood Ca2+ levels, whereas calcitoninlowers blood Ca2+ levels. Calcium Homeostasis Process 1.Decreased blood Ca2+ stimulates PTH secretion from parathyroid glands. 2.PTH stimulates osteoclasts to break down bone and release Ca2+ into the blood. 3.In the kidneys, PTH increases Ca2+ reabsorption from the urine. PTH also stimulates active Vitamin D formation. 4.Vitamin D promotes Ca2+ absorption from the small intestine into the blood. 5.Increased blood Ca2+ stimulates calcitonin secretion from the thyroid gland. 6.Calcitonin inhibits osteoclasts, which allows for enhanced osteoblast uptake of Ca2+ from the blood to deposit into bone. V. GENERAL CONSIDERATIONS OF BONE ANATOMY Anatomical Terms for Features of BonesTermDescription Major FeaturesBody, shaft main portion Head enlarged (often rounded) end Neck constricted area between head and body Margin, border edgeAngle bend Ramus branch off the body beyond the angle Condyle smooth, rounded articular surface Facet small, flattened articular surface Ridges Line, linea low ridge Crest, crista prominent ridge Spine very high ridge Projections Process prominent projection Tubercle small, rounded bump Tuberosity, tuber knob; larger than a tubercle Trochanter tuberosity on the proximal femur Epicondyle enlargement near or above a condyle Lingula flat, tongue-shaped process Hamulus hook-shaped process Cornu horn-shaped process Openings Foramen hole Canal, meatus tunnel Fissure cleft Sinus, labyrinth cavity Depressions Fossa general term for a depression Notch depression in the margin of a bone Fovea little pit Groove, ulcus deep, narrow depression Axial Skeleton (80 Bones) SKULL (CRANIUM) (22 BONES)Braincase (neurocranium) Parietal 2 Temporal 2 Frontal 1 Occipital 1 Sphenoid 1 Ethmoid 1 Face (viscerocranium)Maxilla 2 Zygomatic 2 Palatine 2 Nasal 2 Lacrimal 2 Inferior nasal concha 2 Mandible 1 Vomer 1 AUDITORY OSSICLES (6 BONES)Malleus 2 Incus 2 Stapes 2 HYOID (1 BONE)VERTEBRAL COLUMN (26 BONES)Cervical Vertebrae 7 Thoracic Vertebrae 12
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB Lumbar Vertebrae 5 Sacrum 1 Coccyx 1 THORACIC CAGE (25 BONES)Ribs 24 Sternum (3 parts, sometimes considered 3 bones) 1 Appendicular Skeleton (126 Bones) GIRDLE AND UPPER LIMB (64 BONES)Pectoral Girdle Scapula 2 Clavicle 2 Upper Limb Humerus 2 Ulna 2 Radius 2 Carpal bones 16 Metacarpal bones 10 Phalanges 28 GIRDLE AND LOWER LIMB (62 BONES)Pelvic Girdle Coxal bone 2 Lower Limb Femur 2 Tibia 2 Fibula 2 Patella 2 Tarsal bones 14 Metatarsal bones 10 Phalanges 28 TOTAL BONES: 206 VI. AXIAL SKELETON ‑falls on the axis of the body ‑composed of the skull, auditory ossicles, hyoid bone, vertebral column, and thoracic cage ‑protects the brain, the spinal cord, and the vital organs housed within the thorax A. Skull ‑superior portion of the axial skeleton ‑protects the brain and houses the eyes, ears, nose, and mouth ‑calvaria/skullcap-top of the skull ‑composed of 22 bonesdivided into: •Braincase/neurocranium (8) •Facial bones/viscerocranium (14) Lateral View Frontal View
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB PROCESSES AND OTHER FEATURES OF THE SKULL Feature Location Description External Features Alveolar process Mandible, maxilla Ridges on the mandible and maxilla containing the teeth Angle Mandible Posterior, inferior corner of the mandible Coronoid process Mandible Attachment point for the temporalis muscle Mental protuberance Mandible Chin (resembles a bent knee) Horizontal plate Palatine Posterior third of the hard palate Mandibular condyle Mandible Region where the mandible articulates with the skull Mandibular fossa Temporal Depression where the mandible articulates with the skull Mastoid process Temporal Enlargement posterior to the ear; attachment site for several muscles that move the head Nuchal lines Occipital Attachment points for several posterior neck muscles Occipital condyle Occipital Point of articulation between the skull and the vertebral column Palatine process Maxilla Anterior two-thirds of the hard palate Pterygoid hamulus Sphenoid Hooked process on the inferior end of the medial pterygoid plate, around which the tendon of one palatine muscle passes; an important dental landmark Pterygoid plates (medial and lateral) Sphenoid Hooked process on the inferior end of the medial pterygoid plate, around which the tendon of one palatine muscle passes; an important dental landmark Ramus Mandible Portion of the mandible superior to the angle Styloid process Temporal Attachment site for three muscles (to the tongue, pharynx, and hyoid bone) and some ligaments Temporal lines Parietal Attachment site for the temporalis muscle, which closes the jaw Internal Features Crista galli Ethmoid Process in the anterior part of the braincase to which one of the connective tissue coverings of the brain (dura mater) connects Petrous portion Temporal Thick, interior part of temporal bone containing the middle and inner ears and the auditory ossicles Sella turcica Sphenoid Bony structure, resembling a saddle, in which the pituitary gland is located Braincase/Neurocranium •Frontal bone-comprised anterior 1/3 of cranium; entire forehead; frontal sinus is found oSinus-potential space which makes the skull light weight •Parietal bones-left and right; form the middle segment •Temporal bone-forms the sides of the cranium; it extends inward forming the floor of cranial canal oexternal auditory canal-ear canal; a canal that enables sound waves to reach the eardrum •Occipital bone-posterior aspects of the cranium oForamen magnum-part of occipital bone; hole where spinal cord joins brainstem •Sphenoid bone-found a little deeper inside the skull; butterfly shaped appearance; composed of two main parts: greater wing and lesser wing •Ethmoid bone-middle portion of the cranial floor Sutures: •sagittal suture-where two parietal bones meet •coronal suture-where parietal and frontal bone connects •lambdoidal suture-where parietal and occipital bone connects •squamous suture-connects parietal and temporal bone
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB Facial Bones •Maxilla-upper jawbone; gives support to the face from the eyes down to the mouth •Palatine bones-hard palate (roof of the mouth) •Zygomatic bones-cheek bones; forms the lower orbit; floor of the eyes ozygomatic arch-forms a bridge across the side of the face and provides a major attachment site for a muscle moving the mandible •Lacrimal bones-medial wall of the orbit •Nasal bones-upper third of nose •Inferior nasal conchae-also called turbinate; thin curved bones projecting medially •Vomer-forms the lower portion of the nasal septum •Mandible-lower jawbone; only movable bone in the face oTemporomandibular joint (TMJ)-where mandible connects with the temple to allow jaw movement Bones Forming the Orbit •Frontal –roof •Sphenoid –roof and posterolateral wall •Zygomatic –lateral wall •Maxilla –floor •Lacrimal –medial wall •Ethmoid –medial wall •Palatine –medial wall Bones Forming the Nasal Cavity •Frontal –roof •Nasal –roof •Sphenoid –roof •Ethmoid –roof, septum, lateral wall •Inferior nasal concha –lateral wall •Lacrimal –lateral wall •Maxilla –floor •Palatine –floor and lateral wall •Vomer –septum Inferior View Superior View
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB SKULL FORAMINA, FISSURES, AND CANALS Opening Location Structures Passing Through Openings Carotid canal Temporal Carotid artery and carotid sympathetic nerve plexus Ethmoidal foramina, anterior and posterior Between frontal and ethmoid Anterior and posterior ethmoidal nerves External auditory canal Temporal Sound waves en route to the eardrum Foramen lacerum Between temporal, occipital, and sphenoid The foramen is filled with cartilage during life; the carotid canal and pterygoid canal cross its superior part but do not actually pass through it Foramen magnum Occipital Spinal cord, accessory nerves, and vertebral arteries Foramen ovale Sphenoid Mandibular division of trigeminal nerve Foramen rotundum Sphenoid Maxillary division of trigeminal nerve Foramen spinosum Sphenoid Middle meningeal artery Hypoglossal canal Occipital Hypoglossal nerve Incisive foramen (canal) Between maxillae Incisive nerve Inferior orbital fissure Between sphenoid and maxilla Infraorbital nerve and blood vessels and zygomatic nerve Infraorbital foramen Maxilla Infraorbital nerve Internal auditory canal Temporal Facial nerve and vestibulocochlear nerve Jugular foramen Between temporal and occipital Internal jugular vein, glossopharyngeal nerve, vagus nerve, and accessory nerve Mandibular foramen Mandible Inferior alveolar nerve to the mandibular teeth Mental foramen Mandible Mental nerve Nasolacrimal canal Between lacrimal and maxilla Nasolacrimal (tear) duct Olfactory foramina Ethmoid Olfactory nerves Optic canal Sphenoid Optic nerve and ophthalmic artery Palatine foramina, anterior and posterior Palatine Palatine nerves Pterygoid canal Sphenoid Sympathetic and parasympathetic nerves to the face Sphenopalatine foramen Between palatine and sphenoid Nasopalatine nerve and sphenopalatine blood vessels Stylomastoid foramen Temporal Facial nerve Superior orbital fissures Sphenoid Oculomotor nerve, trochlear nerve, ophthalmic division of trigeminal nerve, abducens nerve, and ophthalmic veins Supraorbital foramen or notch Frontal Supraorbital nerve and vessels Zygomaticofacial foramen Zygomatic Zygomaticofacial nerve Zygomaticotemporal foramen Zygomatic Zygomaticotemporal nerve Paranasal Sinuses B. Auditory Ossicles ‑smallest bones in the body ‑amplifies sound and change the information from sound to vibration •malleus(hammer) •incus(anvil) •stapes(stirrup)
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB C. Hyoid ‑not part of skull and vertebral column ‑found near the throat ‑u-shaped bone which functions as an attachment for tongue muscle ‑floating bone; not attached to other boneD. Vertebral Column ‑composed of 26 irregular bones called vertebrae•7cervical vertebrae •12thoracic vertebrae •5lumbar vertebrae •1sacral bone (5 fused) •1coccyx bone (4 fused) ‑functions: •supports the weight of the head and trunk •protects the spinal cord •allows spinal nerves to exit the spinal cord •provides a site for muscle attachment •permits movement of the head and trunk Four major curvatures: •cervical curve (anteriorly) •thoracic curve (posteriorly) •lumbar curve (anteriorly) •sacral curve (posteriorly) CLIINICAL IMPACT Abnormal Spinal Curvatures •Lordosis-inward curvature of the spine; swayback; abnormal anterior curvature •Kyphosis-outward curvature of the spine; hunchback; abnormal posterior curvature •Scoliosis-sideways curvature; abnormal lateral curvature Typical Vertebra ‑appearance of all vertebrae except C1, C2, sacrum, and coccyx General Structure of a Vertebra Feature Description Body Disk-shaped; usually the largest part with flat surfaces directed superiorly and inferiorly; forms the anterior wall of the vertebral foramen; intervertebral disks are located between the bodies Vertebral foramen Hole in each vertebra through which the spinal cord passes; adjacent vertebral foramina form the vertebral canal
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB Vertebral arch Forms the lateral and posterior walls of the vertebral foramen; possesses several processes and articular surfaces Pedicle Foot of the arch with one on each side; forms the lateral walls of the vertebral foramen Lamina Posterior part of the arch; forms the posterior wall of the vertebral foramen Transverse process Process projecting laterally from the junction of the lamina and pedicle; a site of muscle attachment Spinous process Process projecting posteriorly at the point where the two laminae join; a site of muscle attachment; strengthens the vertebral column and allows for movement Articular processes Superior and inferior projections containing articular facets where vertebrae articulate with each other; strengthen the vertebral column and allow for movement Intervertebral notches Form intervertebral foramina between two adjacent vertebrae through which spinal nerves exit the vertebral canal Cervical Vertebrae ‑have small bodies, except for the atlas, which has no body ‑dislocations and fractures are more common in this area ‑C7has the longest spinous process ‑Whiplash-traumatic hyperextension of the cervical vertebrae Atlas (C1) ‑1st cervical vertebra ringlike vertebra that carries the skull/head‑has no body and no spinous process, but it has large superior facets Axis (C2)‑2nd cervical vertebra ‑rotates head ‑densor odontoid process -pierces through the atlas to act as pivot for the rotation of C1 and skull Thoracic Vertebrae ‑possess long, thin spinous processes that are directed inferiorly ‑have extra articular facets on their lateral surfaces that articulate with the ribs Lumbar Vertebrae ‑have large, thick bodies and heavy, rectangular transverse and spinous processes ‑low back pain and other medical ailments are more common in this area Sacral Vertebrae ‑five vertebrae fused into a single bone called the sacrum•alae-wing-shaped areas in the superior surfaces of the lateral parts
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB •auricular surfaces-ear-shaped in the lateral surfaces •median sacral crest-fusion of spinous processes of the first four sacral vertebrae •sacral hiatus-usually the site of anesthetic injections •transverse lines-where the individual sacral vertebrae fuse •sacral promontory-bulges of the anterior edge of the body of first sacral vertebra Coccyx ‑inferior portion ‑also called as tail bone‑usually consists of three to five semi-fused vertebrae that form a triangle, with the apex directed inferiorly Comparison of Vertebral Regions Feature Cervical Thoracic Lumbar Body Absent in C1, small in others Medium-sized with articular facets for ribs Large Transverse process Transverse foramen Articular facets for ribs, except T11 and T12 Square Spinous process Absent in C1, bifid in others, except C7 Long, angled inferiorly Square Articular facets Face superior/ inferior Face obliquely Face medial/ lateral Intervertebral Discs ‑pads of fibrocartilage that separates the vertebral bodies‑provide additional support and prevent the vertebral bodies from rubbing against each other ‑consist of:•externalannulus fibrosus •internal,gelatinousnucleus pulposus E. Rib Cage ‑protects vital organs within the thorax and prevents the collapse of the thorax during respiration ‑made up of 25 bones: •12pairsof ribs •1sternum Ribs and Costal Cartilages True ribs(1-7) ‑aka vertebrosternal; superior 7 pairs ‑attached directly to the sternum through costal cartilageFalse ribs (8-12) ‑inferior 5 pairs ‑do not directly connect to the sternum •Vertebrochondral ribs (8-10)-upper 3 pairs; indirectly connected to the sternum •Floating ribs (11-12) -aka vertebral ribs; lower 2 pairs; not connected at all Sternum ‑breastbone ‑divided into three parts: •Manubrium •Sternal body/ Gladiolus •Xiphoid process Sternal notch-separation of manubrium and gladiolus Jugular notch-aka suprasternal notch; between the ends of the clavicle which articulates with the sternum Sternal angle-slight elevation in the sternum; important landmark for locating the second ribs
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB VII. APPENDICULAR SKELETON ‑consists of the bones of the upper and lower limbs, as well as the girdles, which attach the limbs to the axial skeleton ‑upper extremity (64bones) ‑lower extremity (62bones) A. Pectoral Girdle ‑consists of four bones (2 scapulae and 2 clavicles) Scapula‑or shoulder blade ‑connects the upper extremity to the trunk only by the clavicle ‑flat, triangular bone with three large fossae where muscles extending to the arm are attached •glenoid cavity-fourth fossa where the head of the humerus connects to the scapula •acromion process -form a protective cover for the shoulder joint; form the attachment site for the clavicle; provide attachment •points for some of the shoulder muscles Clavicle‑or collar bone ‑attached to the sternum ‑a long bone with a slight sigmoid (S-shaped) curve B. Upper limb‑consists of the bones of the arm, forearm, wrist, and hand Arm ‑region between the shoulder and the elbow Humerus‑large, long bone of the arm Anatomy of Humerus Parts Description head rounded proximal portion anatomical neck around the edge of the humeral head surgical neck located at the proximal end of the humeral shaft greater tubercle bump; for muscle attachment lesser tubercle for muscle attachment intertubercular groove/bicipital groove groove between the two tubercles that contains one tendon of the biceps brachii muscle deltoid tuberosity muscle attachment for deltoid muscle; protruded capitulum lateral portion of the articular surface; articulates with the radius trochlea medial portion; articulates with the ulna lateral and medial epicondyles points of attachment for the muscles of the forearm Forearm Radius‑lateral bone that articulates with capitulum Ulna ‑medial to the radius; longer bone than radius •trochlear notch -fits over the trochlea of the humerus •olecranon process -elbow •coronoid process-helps complete the “grip” of the ulna •styloid process -where ligaments of the wrist are attached •radial tuberosity-where biceps brachii attaches
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB Wrist Carpals •Scaphoid(boat-shaped) •Lunate(moon-shaped) •Triquetrum(three-cornered) •Pisiform(pea-shaped) •Hamate(has a hooked process) •Capitate(head-shaped) •Trapezoid(similar to a four-sided geometric form with two parallel sides) •Trapezium(named after a four-sided geometric form with no two sides parallel) So Long Top Part, Here ComesThe Thumb Hand •Metacarpal(hands) •Phalanges(fingers) C. Pelvic Girdle ‑where lower limbs attach to body ‑3 bones fused as one •ilium -most lateral and most superior part of pelvic girdle; bowl like wall of pelvis•ischium-inferior and posterior region •pubis- hip socket (joint) •Pelvis-includes pelvic girdle and coccyx oFalse pelvis/Pelvis minor-part of pelvic girdle that is above the pelvic inlet oTrue pelvis/Pelvis major-part of pelvic girdle that is below the pelvic inlet •iliac crest-can be seen along the superior margin of each ilium •acetabulum -socket of the hip joint •obturator foramen -large hole in each hip bone Differences Between the Male Pelvis and the Female Pelvis Female pelvis-wider than male designed for childbearing Area Description General In females, somewhat lighter in weight and wider laterally but shorter superiorly to inferiorly and less funnel-shaped; less obvious muscle attachment points in females Sacrum Broader in females, with the inferior part directed more posteriorly; the sacral promontory does not project as far anteriorly in females Pelvic inlet Heart-shaped in males; oval in females Pelvic outlet Broader and more shallow in females Subpubic angle Less than 90 degrees in males; 90 degrees or more in females Ilium More shallow and flared laterally in females Ischial spines Farther apart in females Ischial tuberosities Turned laterally in females and medially in males D. Lower Limb ‑consists of the bones of the thigh, leg, ankle, and foot Thigh Femur ‑longest bone; region between the hip and the knee •head of femur-large spherical enlargement; attached to pelvic bone •greater trochanter and lesser trochanter-bump for muscle attachment •linea espera-ridge or depression running through the shaft/body of the bone •lateral epicondyle -for support Patella ‑knee cap; enables the tendon to bend over the knee; sesamoid bone
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB Leg •Tibia-larger and major weight-bearing bone of the leg •Fibula-smaller; more lateral bone Ankle and Foot •Tarsals -ankle •Metatarsals -foot •Phalanges -toes and fingers Tarsals •Calcaneus •Talus •Navicular •Cuboid •Cuneiforms VIII. JOINTS Joints ‑also called as articulations ‑where 2 or more bones join together Can be classified according to: •Structure oFibrous oCartilaginous oSynovial •Function oSynarthroses (non-movable) oAmphiarthroses (slightly movable) oDiarthroses (freely movable) Classification According to Structure: Fibrous Joints ‑where 2 bones are united by fibrous connective tissue ‑no joint cavity and has no movement ‑simply bind bones together 3 Types: •Suture-joints between 2 flat bones, connects the cranial bones oFontanels-soft spot in the skull of an infant; because of immaturity; allows childbirth •Syndesmosis-bands of fibrous tissue that binds 2 bones separated by some distance and held together by distance •Gomphosis-joint between tooth and socket; held together by ligaments Cartilaginous Joints ‑where 2 bones are united by cartilage ‑provides slight movement 2 Types: •Synchondrosis-hyaline cartilage, immovable (example: costal cartilage) •Symphysis-fibrocartilage, compressible fibrocartilaginous pad that connects two bones; slight movement (example: intervertebral disk, pubis symphysis) Synovial Joints ‑freely movable joints ‑forms a cavity between 2 bones containing fluid called synovial fluid ‑usually found in appendicular bones
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB Several Features of Synovial Joints: •Articular cartilage -covers the articular surfaces of bones within synovial joints •Joint cavity-space in between •Joint capsule -surrounds the cavity, which helps hold the bones together while still allowing movement•Synovial membrane -lines the joint cavity everywhere except over the articular cartilage •Synovial fluid -forms a thin, lubricating film covering the surfaces of the joint •Bursa-lining of joint capsule oBursitis-inflammation of bursa 6 Types: •Gliding-plane joints; consist of two opposed fat surfaces that glide over each other Example: articular facets between vertebrae •Hinge-permit movement in one plane only; consist of a convex cylinder of one bone applied to a corresponding concavity of the other bone Example: elbow and knee joint •Pivot-restrict movement to rotation around a single axis; consists of a cylindrical bony process that rotates within a ring composed partly of bone and partly of ligament Example: shaking the head “no” •Ellipsoid-condyloid joints; elongated ball-and-socket joints; shape of the joint limits its range of movement nearly to that of a hinge motion, but in two planes Example: joint between the occipital condyles of the skull and the atlas •Saddle-consist of two saddle-shaped articulating surfaces oriented at right angles to each other; movement in these joints can occur in two planes Example: between the metacarpal bone and the carpal bone (trapezium) of the thumb •Ball and Socket-allows a wide range of movement in almost any direction; consist of a ball (head) at the end of one bone and a socket in an adjacent bone into which a portion of the ball fits Example: shoulder and hip joints Fetal Skull •made up of partly ossified skull bones and largely of fibrous and cartilaginous tissue •Sutures-lines of union •Fontanels-fibrous spaces between bone which have not completely united
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB •Sphenoidal (2) •Posterior •Anterior •Mastoid (2) Joint Movement •Flexion-decreasing the angle of joints to bring articulating bones closer or to bend •Extension-straightening movement that increases angle of joints to extend articulating bones (normal position) •Hyperextension-extension beyond 180 degrees; can be normal but can also result in injury •Dorsiflexion-movement of foot towards the shin •Plantar flexion-pointing toes •Abduction-movement of away from mid-sagittal line/midline •Adduction-movement towards the midline •Pronation-rotation of forearm so the palm is faced down •Supination-palm face up •Eversion-plantar surface turns laterally •Inversion-plantar surface faces medially •Rotation-turning of a structure around its long axis; as in shaking the head to say “no”•Circumduction-moving the distal end of an extremity in a circle •Protraction-moving a part anteriorly •Retraction-moving a part posteriorly
Chapter 6: Skeletal System: Bone and Joints @medtech.files | by MAPB •Elevation-raising a part •Depression-lowering a part IX. EFFECTS OF AGING ON THE SKELETAL SYSTEM AND JOINTS1.Bone matrix becomes more brittle and decreases in total amount during aging. 2.Joints lose articular cartilage and become less flexible with age. 3.Prevention measures include exercise and calcium and vitamin D supplements. X. DISEASES Condition Description Tumors May be malignant or benign and cause a range of bone defects Gigantism Abnormally increased body size due to excessive growth at the epiphyseal plates Dwarfism Abnormally small body size due to improper growth at the epiphyseal plates Osteogenesis imperfecta Brittle bones that fracture easily due to insufficient or abnormal collagen Rickets Growth retardation due to nutritional deficiencies in minerals (Ca2+) or vitamin D; results in bones that are soft, weak, and easily broken Osteomyelitis Bone inflammation often due to a bacterial infection that may lead to complete destruction of the bone Tuberculosis Typically, a lung bacterium that can also affect bone Osteomalacia Softening of adult bones due to calcium depletion; often caused by vitamin D deficiency Osteoporosis Reduction in overall quantity of bone tissue Arthritis Inflammation of a joint, leading to pain and stiffness of the joint; over 100 causes, including infectious agents, metabolic disorders, trauma, and immune disorders Degenerative joint disease (osteoarthritis) Most common type of arthritis; affects 85% of Americans over age 70; characterized by gradual degeneration of a joint with advancing age; can be delayed with exercise Rheumatoid arthritis General connective tissue autoimmune disorder that predominantly affects joints Gout Group of metabolic disorders that lead to increased production and accumulation of uric acid crystals in tissues, including joint capsules; can lead to arthritis Lyme disease Caused by a bacterial infection that affects multiple organs, including the joints; can lead to chronic arthritis Bursitis Inflammation of a bursa, often due to forceful contact or prolonged contact, such as student’s elbow from leaning on a deskBunion Most bunions are deformations of the first metatarsal (the great toe); bursitis may accompany this deformity; irritated by tight shoes Tendinitis Inflammation of tendon sheaths, often from overuse, such as tennis elbow Dislocation Movement of bones out of their correct alignment at a joint; a partial dislocation is a subluxation Sprain Stretching or tearing of ligaments supporting a joint
Human Anatomy and Physiology with Pathophysiology CHAPTER 7: MUSCULAR SYSTEMChapter 7: Muscular System @medtech.files | by MAPB OUTLINE I.Functions of the Muscular SystemII.General Properties of Muscle Tissue III.Characteristics of Skeletal Muscle A.Skeletal Muscle Structure B.Excitability of Muscle Fibers C.Nerve Supply and Muscle Fiber Stimulation D.Muscle Contraction E.Energy Requirements for Muscle Contraction F.Fatigue G.Effect of Fiber Type on Activity Level IV.Smooth Muscle and Cardiac Muscle V.Skeletal Muscle Anatomy A.General Principles B.Nomenclature C.Muscles of the Head and Neck D.Trunk Muscles E.Upper Limb Muscles F.Lower Limb Muscles VI.Effects of Aging on Skeletal Muscle VII.DiseasesI. FUNCTIONS OF THE MUSCULAR SYSTEM 1.Movement of the body(contraction of skeletal muscle) 2.Maintenance of posture(skeletal muscles constantly maintain tone) 3.Respiration (muscles of the thorax carry out breathing movements) 4.Production of body heat(heat is a by-product of contraction) 5.Communication(speaking, writing, typing, gesturing, and facial expressions) 6.Constriction of organs and vessels (contraction of smooth muscle causes organs to constrict that help in digestive tract, secretions, and blood flow) 7.Contraction of the heart (contraction of heart muscle causes heart to beat) II. GENERAL PROPERTIES OF MUSCLE TISSUE 1.Contractility-the ability of muscle to shorten forcefully, or contract •Skeletal: causes the structures to which they are attached to move •Smooth and cardiac: increases pressure inside the organ it surrounds 2.Excitability-the capacity of muscle to respond to a stimulus •Skeletal: the stimulus to contract is from nerves that we consciously control •Smooth and cardiac: contract spontaneously, but also receive involuntary neural signals and hormonal signals to modulate force or rate of contraction 3.Extensibility-muscle can be stretched beyond its normal resting length and still be able to contract 4.Elasticity-the ability of muscle to recoil to its original resting length after it has been stretched Comparison of Muscle Types Skeletal MuscleSmooth MuscleCardiac MuscleLocation attached to bones walls of hollow organs, blood vessels, and glands heart Appearance Cell Shape Long, cylindrical Spindle-shaped Branched, cylindrical Nucleus Multiple, peripherally located Single, centrally located Single, centrally located Special Intercellular Connections Gap junctions Intercalated disks Striations Yes No Yes Autorhythmic No Yes Yes Control Voluntary Involuntary Involuntary Function Move the whole body Move food through digestive tract; empty urinary bladder, regulate blood vessel diameter, contract many gland ducts Contract heart to pump blood through the body III. CHARACTERISTICS OF SKELETAL MSUCLE A. Skeletal Muscle Structure •Skeletal muscle-or striated muscle; constitutes approximately 40% of body weight; attached to the skeletal system
Chapter 7: Muscular System @medtech.files | by MAPB Connective Tissue Coverings of Muscle •Epimysium-connective tissue sheath that surrounds each skeletal muscle; also called as muscle fascia •Muscle fascicles-multiple subdivided bundles of a whole muscle •Perimysium-loose connective tissue that separates each fascicle •Endomysium-surrounds each muscle fiber Muscle Fiber Structure Muscle fiber-a single cylindrical cell, with several nuclei located at its periphery •sarcolemma-cell membrane of muscle fiber with many tubelike inward folds •transverse tubules -or T tubules; tubelike inward folds of sarcolemma; occur at regular intervals along the muscle fiber and extend to the center of muscle fiber •sarcoplasmic reticulum-enlarged portions of the smooth endoplasmic reticulum; has a high concentration of Ca2+, which plays a major role in muscle contraction •terminal cisternae-enlarged portions •sarcoplasm -cytoplasm of a muscle fiber; contains bundles of protein filaments •myofibrils -bundles of protein filaments within sarcoplasm oactin myofilaments omyosin myofilaments Sarcomeres Sarcomere-basic structural and functional unit of a skeletal muscle; smallest portion capable of contracting •z disks -separate one sarcomere from the next; network of protein fibers that forms a stationary anchor for actin to attach •I bands -light-staining bands; consist of only actin myofilaments •A band -central dark-staining band; actin and myosin myofilaments overlap for some distance on both ends •H zone -smaller, lighter-staining region in the center of each A band; contains only myosin myofilaments •M line-consists of fine protein filaments that anchor the myosin myofilaments in place Actin and Myosin Myofilaments Actin myofilaments-or thin filaments, are made up of three components: •actin strands-have attachment sites for the myosin myofilaments •troponin-have binding sites for Ca2+; attached at specific intervals along the actin myofilaments •tropomyosin-block the myosin myofilament binding sites on the actin myofilaments; cover the attachment sites on the actin myofilament if no Ca2+ is present Myosin myofilaments-or thick myofilaments; resemble bundles of tiny golf clubs •myosin heads-bind to attachment sites on the actin myofilaments; bend and straighten during contraction; break down ATP, releasing energy B. Excitability of Muscle Fibers polarized cell-the inside of most cell membranes is negatively charged compared with the outside; creates an electrical charge difference across the cell membrane resting membrane potential-electrical charge difference across the cell membrane of an unstimulated cell
Chapter 7: Muscular System @medtech.files | by MAPB Resting membrane potential exists because of the ff: 1.K+ is higher inside the cell membrane 2.Na+ is higher outside of cell membrane 3.many negatively charged molecules, such as proteins, inside the cell are too large to diffuse across 4.cell membrane is more permeable to K+ than it is to Na+; electrically excitable cells have many K+ leak channels. Ion Channels and the Action Potential 1.Resting membrane potential -Na+ channels and some, but not all, K+ channels are closed; inside of cell membrane –negatively charged 2.Depolarization -Na+ channels are open; inside of the cell membrane –positively charged 3.Repolarization-Na+ channels are closed; more K+ channels open; inside of the cell membrane –negatively charged •depolarization -increase in positive charge inside the cell membrane •action potential-rapid change in charge across the cell membrane •repolarization -due to the exit of K+ from the cell C. Nerve Supply and Muscle Fiber Stimulation •Motor neurons-specialized nerve cells that stimulate muscles to contract; generate action potentials •Neuromuscular junction-junction with a muscle fiber; located near the center of a muscle fiber •Synapse -refers to the cell-to-cell junction between a nerve cell and either another nerve cell or an effector cell •Motor unit-constituted by a single neuron and all the skeletal fibers it innervates; fewer fibers the more it is controllable •Presynaptic terminal-the axon terminal •Synaptic cleft-space between presynaptic terminal and the muscle fiber membrane •Postsynaptic membrane-the sarcolemma •synaptic vesicles-small vesicles found in each presynaptic terminal; contain neurotransmitter called acetylcholine (ACh) •neurotransmitters -stimulate or inhibit postsynaptic cells Function of the Neuromuscular Junction 1.An action potential arrives at the presynaptic terminal, causing Ca2+ channels to open. 2.Calcium ions (Ca2+) enter the presynaptic terminal and initiate the release of a neurotransmitter, acetylcholine (ACh), from synaptic vesicles into the presynaptic cleft. 3.Diffusion of ACh across the synaptic cleft and binding of ACh to ACh receptors on the postsynaptic muscle fiber membrane opens Na+ channels. 4.Sodium ions (Na+) diffuse down their concentration gradient, which results in depolarization of the muscle fiber membrane; if threshold has been reached, a postsynaptic action potential results. acetylcholinesterase-enzyme that breaks down acetylcholine, preventing overstimulation of muscle fiber D. Muscle Contraction Sliding filament model-process of muscle contraction where actin myofilaments slide past myosin myofilaments cross-bridges -formed by binding of heads of myosin myofilaments to exposed attachment sites on the actin myofilament 1.Muscle contraction all starts with a stimulus or an action potentialwhich runs on the surface of the muscle fiber and goes down the T tubule. 2.This causes a change in the resting membrane potential leading to stimulation of the sarcoplasmic reticulum and results in the release of Calcium ions. 3.Calcium then interacts with myosin and actin to produce contraction. Breakdown of ATP and Cross-Bridge Movement 1.Exposure of active sites 2.Cross-bridge formation 3.Power stroke 4.Cross-bridge release 5.Hydrolysis of ATP 6.Recovery stroke Muscle Twitch, Summation, Tetanus, and Recruitment Muscle twitch-single contraction of a muscle fiber in response to stimulus Three phases: 1.lag phase-or latent phase; time between application of stimulus and beginning of contraction; action potentials have not yet arrived at the sarcolemma 2.contraction phase-time during which the muscle contracts; due to cross-bridge movement and cycling 3.relaxation phase-time during which the muscle relaxes; Ca2+ is actively transported back into the sarcoplasmic reticulum
Chapter 7: Muscular System @medtech.files | by MAPB summation-individual muscles contract more forcefully; prevents relaxation or detachment of cross-bridges; buildup of Ca2+ occurs tetanus-sustained contraction that occurs when the frequency of stimulation is so rapid that no relaxation occurs recruitment-motor units are stimulated, which increases the total number of muscle fibers contracting Fiber Types •slow-twitch fibers-contain type I myosin as the predominant or even exclusive type; contract more slowly; can hold a contraction longer than fast-twitch fibers •fast-twitch fibers-contain either type IIa or type IIb myosin myofilaments; contract quickly otype IIb fibers-fastest; contract ten times faster than slow-twitch (type I) fibers otype IIa fibers-contract at an intermediate speed; can hold contractions longer than type IIb Slow-Twitch (Type I) Fast-Twitch Oxidative Glycolytic (Type IIa) Fast-Twitch Glycolytic (Type IIb) Fiber Diameter Smallest Intermediate Largest Myoglobin Content High High Low Mitochondria Many Many Few Metabolism High aerobic capacity High anaerobic capacity; intermediate aerobic capacity Highest anaerobic capacity Fatigue Resistance High Intermediate Low Myosin Head Activity Slow Fast Fast Glycogen Concentration Low High High Functions Maintenance of posture; endurance activities Endurance activities in endurance-trained muscles Rapid, intense movement of short duration (sprinting) E. Energy Requirements for Muscle ContractionATP is derived from four processes in skeletal muscle: 1.Aerobic production of ATP during most exercise and normal conditions 2.Anaerobic production of ATP during intensive short-term work 3.Conversion of a molecule called creatine phosphate to ATP 4.Conversion of two ADP to one ATP and one AMP (adenosine monophosphate) during heavy exercise Aerobic respiration-occurs mostly in mitochondria; requires O2 and breaks down glucose to produce ATP, CO2, and H2O; can also process lipids or amino acids to make ATP Anaerobic respiration-does not require O2, breaks down glucose to produce ATP and lactate F. Fatigue Fatigue-temporary state of reduced work capacity; without this, muscle fibers would be worked to the point of structural damage to them and their supportive tissues •synaptic fatigue-exhaustion of nerve transmitters •muscular fatigue-intense exercise that increase ROS which triggers IL-6 that most likely to cause muscle soreness •CNS fatigue-motor neurons in the brain do not function as they should •physiological contracture-muscle becomes incapable of either contracting or relaxing; too little ATP to bind myosin myofilaments •physiological fatigue-involves CNS rather than the muscles G. Effect of Fiber Type on Activity Level •myoglobin-stores oxygen temporarily •hypertrophy-enlargement of muscle fibers because exercise increases the blood supply to muscles, the number of mitochondria per muscle fiber, and the number of myofibrils and myofilament •atrophy-decrease in muscle fiber size Types of Muscle Contractions Isometric contraction‑length of muscle does not change, but amount of tension increase Isotonic contraction‑the amount of tension is constant, but the length of muscle decreases •concentric contraction-isotonic contraction in which muscle tension increases as muscle shortens •eccentric contractions-tension is maintained on muscle but opposing resistance causes the muscle to lengthen
Chapter 7: Muscular System @medtech.files | by MAPB Muscle Tone •Muscle tone-constant tension produced by body muscles over long periods of time IV. SMOOTH MUSCLE AND CARDIAC MUSCLE •Smooth muscle -small and spindle-shaped, usually with one nucleus per cell; not striated; have gap junctionsoAutorhythmicity-resulting periodic spontaneous contraction of smooth muscle •Cardiac muscle-long, striated, and branching, with usually only one nucleus per cell; ointercalated disks-specialized structure of cardiac muscle; allow action potentials to be conducted directly from cell to cell V. SKELETAL MUSCLE ANATOMY A. General Principles •tendon-connects muscle to bone •aponeuroses-broad, sheetlike tendons •retinaculum-band of connective tissue that holds down the tendons at each wrist and ankle •origin-most stationary, or fixed end of the muscle •insertion-end of the muscle attached to the bone undergoing the greatest movement •belly-part of muscle between origin and insertion •muscle’s action-specific body movement caused by muscle contraction •agonists-group of muscles that does action •antagonists-group of muscles that opposed the action of other group of muscles •synergists-member of a group of muscles working together to produce movements •primemover-one muscle that plays the major role in accomplishing the desired movement •fixators-muscles that hold one bone in place relative to the body while a usually more distal bone is moved B. Nomenclature 1. Location •pectoralis-located in the chest •gluteus muscle-located in the buttocks •brachial muscle-located in the arm 2. Size •gluteus maximus-largest muscle of the buttock •gluteus minimus-the smallest •longus-long muscle •brevis-short muscle 3. Shape •deltoid-triangular in shape •quadratus (quadrate) muscle-rectangular •teres muscle-round 4. Orientation of fascicles •rectus (straight, parallel) muscle has muscle fascicles running in the same direction as the structure with which the muscle is associated •fascicles of an oblique muscle lie at an angle to the length of the structure Pattern of Fascicle Arrangement •Circular-fascicles arranged in a circle around an opening; act as sphincters to close the opening •Convergent -broadly distributedfascicles convergeat a single tendon •Parallel -Fascicles lie parallel to one another and to the long axis of the muscle •Pennate-fascicles originate from a tendon that runs the length of the entire muscle Three different patterns: oUnipennate-fascicles on only one side of the tendon oBipennate-fascicles on both sides of the tendon oMultipennate-fascicles arranged at many places around the central tendon. Spread out at angles to many smaller tendons •Fusiform-fascicles lie parallel to long axis of muscle. Belly of muscle is larger in diameter than ends 5. Origin and insertion •sternocleidomastoid-origin on the sternum and clavicle; insertion on the mastoid process of the temporal bone •brachioradialis-originates in the arm (brachium) and inserts onto the radius 6. Number of heads •biceps muscle-has two heads (origins) •triceps muscle-has three heads (origins) 7. Function •abduction-moves a structure away from the midline •adduction-moves a structure toward the midline
Chapter 7: Muscular System @medtech.files | by MAPB C. Muscles of the Head and Neck Muscles of Facial Expression MUSCLEORIGININSERTIONACTIONBuccinator Maxilla and mandible Orbicularis oris at corner of mouth Draws corner of mouth posteriorly; compresses cheek to hold food between teeth Depressor anguli oris Lower border of mandible Skin of lip near corner of mouth Lowers corner of mouth; “frown”Levator labii superioris Maxilla Skin and orbicularis oris of upper lip Raises upper lip; sneer Occipitofrontalis Occipital bone Skin of eyebrow and nose Moves scalp; raises eyebrows Orbicularis oculi Maxilla and frontal bones Circles orbit and inserts onto skin around eyelids Closes eyes; blinking, winking, squinting Orbicularis oris Nasal septum, maxilla, and mandible Fascia and other muscles of lips Closes and purses lips; “kissing”Zygomaticus major Zygomatic bone Angle of mouth Elevates and abducts upper lip and corner of mouth; “smile”Zygomaticus minor Zygomatic bone Orbicularis oris of upper lip Elevates and abducts upper lip; “smile”Muscles of Mastication MUSCLE ORIGIN INSERTION ACTION Temporalis Temporal fossa Anterior portion of mandibular ramus and coronoid process Elevates and draws mandible posteriorly; closes jaw Masseter Zygomatic arch Lateral side of mandibular ramus Elevates and pushes mandible anteriorly; closes jaw Lateral pterygoid Lateral pterygoid plate and greater wing of sphenoid Condylar process of mandible and articular disk Pushes mandible anteriorly and depresses mandible; closes jaw Medial pterygoid Lateral pterygoid plate of sphenoid and tuberosity of maxilla Medial surface of mandible Pushes mandible anteriorly and elevates mandible; closes jaw
Chapter 7: Muscular System @medtech.files | by MAPB Tongue and Swallowing MusclesMUSCLE ORIGIN INSERTION ACTION Tongue musclesIntrinsic Extrinsic Inside tongue Bones around oral cavity or soft palate Inside tongue Onto tongue Changes shape of tongue Moves tongue Hyoid musclesSuprahyoid Infrahyoid Base of skull, mandible Sternum, larynx Hyoid bone Hyoid bone Elevates or stabilizes hyoid Depresses or stabilizes hyoid Soft palate muscles Skull or soft palate Palate, tongue, or pharynx Moves soft palate, tongue, or pharynx Pharyngeal musclesElevators Constrictors Superior Middle InferiorSoft palate and auditory tube Larynx and hyoid Pharynx Pharynx Elevate pharynx Constrict pharynx Neck Muscles MUSCLE ORIGIN INSERTION ACTION Deep neck musclesFlexors ExtensorsAnterior of vertebrae Posterior of vertebrae Base of skull Base of skull Flex head and neck Extend head and neck Sternocleidomastoid Manubrium of sternum and medial part of clavicle Mastoid process and nuchal line of skull Individually rotate head; together flex neck Trapezius Posterior surface of skull and upper vertebral column (C7–T12) Clavicle, acromion process, and scapular spine Extends and laterally flexes neck
Chapter 7: Muscular System @medtech.files | by MAPB D. Trunk Muscles Muscles Acting on the Vertebral Column MUSCLE ORIGIN INSERTION ACTION SuperficialErector spinae divides into three columns: •Iliocostalis •Longissimus •SpinalisSacrum, ilium, vertebrae, and ribs ribs, vertebrae, and skull Extends vertebral column; maintains posture Deep back muscle Vertebrae Vertebrae Extend vertebral column and help bend vertebral column laterally Muscles of the Thorax MUSCLE ORIGIN INSERTION ACTION Scalenes Cervical vertebrae First and second ribs Inspiration; elevate ribs External intercostals Inferior edge of each rib Superior edge of next rib below origin Inspiration; elevate ribs Internal intercostals Superior edge of each rib Inferior edge of next rib above origin Forced expiration; depress ribs Diaphragm Inferior ribs, sternum, and lumbar vertebrae Central tendon of diaphragm Inspiration; depress floor of thorax Muscles of the Abdominal Wall MUSCLE ORIGIN INSERTION ACTION Rectus abdominis Pubic crest and pubic symphysis Xiphoid process and inferior ribs Flexes vertebral column; compresses abdomen External abdominal oblique Ribs 5–12 Iliac crest, inguinal ligament, and fascia of rectus abdominis Compresses abdomen; flexes and rotates vertebral column Internal abdominal oblique Iliac crest, inguinal ligament, and lumbar fascia Ribs 10–12 and fascia of rectus abdominis Compresses abdomen; flexes and rotates vertebral column Transversus abdominis Costal cartilages 7–12, lumbar fascia, iliac crest, and inguinal ligament Xiphoid process, fascia of rectus abdominis, and pubic tubercle Compresses abdomen
Chapter 7: Muscular System @medtech.files | by MAPB Muscles of the Pelvic Floor and Perineum MUSCLE ORIGIN INSERTION ACTION Pelvic FloorLevator ani Posterior pubis and ischial spine Sacrum and coccyx Elevates anus; supports pelvic viscera PerineumBulbospongiosus Ischiocavernosus External anal sphincter Transverse perinei •Deep •Superficialcentral tendon of perineum Ischial ramus Coccyx Ischial ramus Ischial ramus male: dorsal surface of penis and bulb of penis female: base of clitoris Corpus cavernosum Central tendon of perineum Midline connective tissue Central tendon of perineum Constricts urethra; erects penis Erects clitoris Compresses base of penis or clitoris Keeps orifice of anal canal closed Supports pelvic floor Fixes central tendon E. Upper Limb Muscles Muscles Acting on the Scapula MUSCLE ORIGIN INSERTION ACTION Levator scapulae Transverse processes of C1–C4 Superior angle of scapula Elevates, retracts, and rotates scapula; laterally flexes neck Pectoralis minor Ribs 3–5 Coracoid process of scapula Depresses scapula or elevates ribs Rhomboids Major MinorSpinous processes of T1–T4 Medial border of scapula Retracts, rotates, and fixes scapula Retracts, slightly elevates, rotates, and fixes scapula Serratus anterior Ribs 1–9 Medial border of scapula Rotates and protracts scapula; elevates ribs Trapezius Posterior surface of skull and spinous processes of C7–T12 Clavicle, acromion process, and scapular spine Elevates, depresses, retracts, rotates, and fixes scapula; extends neck
Chapter 7: Muscular System @medtech.files | by MAPB Arm Movements MUSCLE ORIGIN INSERTION ACTION Deltoid Clavicle, acromion process, and scapular spine of scapula Deltoid tuberosity of humerus Flexes and extends shoulder; abducts and medially and laterally rotates arm Latissimus dorsi Spinous processes of T7–L5, sacrum and iliac crest, and inferior angle of scapula in some people Medial crest of intertubercular groove of humerus Extends shoulder; adducts and medially rotates arm Pectoralis major Clavicle, sternum, superior six costal cartilages, and abdominal muscles Lateral crest of intertubercular groove of humerus Flexes shoulder; extends shoulder from flexed position; adducts and medially rotates arm Teres major Lateral border of scapula Medial crest of intertubercular groove of humerus Extends shoulder; adducts and medially rotates arm Rotator CuffInfraspinatusSubscapularis Supraspinatus Teres minorInfraspinous fossa Subscapular fossa Supraspinous fossa Lateral border Greater tubercle Lesser tubercle Greater tubercle Greater tubercle Stabilize and extend shoulder and laterally rotates arm Stabilize and extend shoulder and medially rotates arm Stabilize shoulder and abducts arm Stabilizes and extends shoulder; adducts and laterally rotates arm Arm Muscles MUSCLE ORIGIN INSERTION ACTION Biceps brachii Long head –supraglenoid tubercle of scapula Short head –coracoid process of scapula Radial tuberosity and aponeurosis of biceps brachii Flexes elbow; supinates forearm; flexes shoulder Brachialis Anterior surface of humerus Coronoid process of ulna Flexes elbow Triceps brachii Long head –lateral border of scapula Lateral head –lateral and posterior surface of humerus Medial head –posterior humerus Olecranon process of ulna Extends elbow; extends shoulder; adducts arm
Chapter 7: Muscular System @medtech.files | by MAPB Forearm Muscles MUSCLE ORIGIN INSERTION ACTION Anterior ForearmPalmaris longusFlexor carpi radialisFlexor carpi ulnarisFlexor digitorum profundusFlexor digitorum superficialisPronator•Quadratus •TeresMedial epicondyle of humerus Medial epicondyle of humerus Medial epicondyle of humerus and ulna Ulna Medial epicondyle of humerus; coronoid process and radius Distal Ulna Medial epicondyle of humerus and coronoid process of ulna Aponeurosis over palm Second and third metacarpal bones Pisiform Distal phalanges of digits 2–5 Middle phalanges of digits 2–5 Distal radius Radius Tightens skin of palm Flexes and abducts wrist Flexes and abducts wrist Flexes fingers and wrist Flexes fingers and wrist Pronates forearm Pronates forearm Posterior ForearmBrachioradialisExtensor carpi radialis brevisExtensor carpi radialis longusExtensor carpi ulnarisExtensor digitorumSupinator Lateral supracondylar ridge of humerus Lateral epicondyle of humerus Lateral supracondylar ridge of humerus Lateral epicondyle of humerus and ulna Lateral epicondyle of humerus Lateral epicondyle of humerus and ulna Styloid process of radius Base of third metacarpal bone Base of second metacarpal bone Base of fifth metacarpal bone Extensor tendon expansion over phalanges of digits 2–5 Radius Flexes elbow Extends and abducts wrist Extends and abducts wrist Extends and abducts wrist Extends fingers and wrist Supinates forearm (and hand)
Chapter 7: Muscular System @medtech.files | by MAPB F. Lower Limb Muscles Muscles Moving the Thigh MUSCLE ORIGIN INSERTION ACTION Iliopsoas Iliac fossa and vertebrae T12–L5 Lesser trochanter of femur and hip capsule Flexes hip Gluteus maximus Posterior surface of ilium, sacrum, and coccyx Gluteal tuberosity of femur and iliotibial tract Extends hip; abducts and laterally rotates thigh Gluteus medius Gluteus minimus Posterior surface of ilium Greater trochanter of femur Abducts and medially rotates thigh Tensor fasciae latae Anterior superior iliac spine Through lateral fascia of thigh to lateral condyle of tibia Steadies femur on tibia through iliotibial tract when standing; flexes hip; medially rotates and abducts thigh Leg Movements MUSCLE ORIGIN INSERTION ACTION Anterior CompartmentQuadriceps femoris •Rectus femoris •Vastus lateralis •Vastus medialis•Vastus intermedius Sartorius Ilium Greater trochanter and linea aspera of femur Linea aspera of femur Body of femur Anterior superior iliac spine Tibial tuberosity via patellar ligament Medial side of tibial tuberosity Extends knee; flexes hip Extends knee Extends knee Extends knee Flexes hip and knee; laterally rotates thigh Medial Compartment Adductor longusAdductor magnusGracilisPubis Pubis and ischium Pubis near symphysis Linea aspera of femur Femur Tibia Adducts and laterally rotates thigh; flexes hip Adducts and laterally rotates thigh; extends knee Adducts thigh; flexes knee
Chapter 7: Muscular System @medtech.files | by MAPB Posterior CompartmentHamstring Muscles •Biceps femoris •Semimembranosus •SemitendinosusLong head –ischial tuberosity Short head –femur Ischial tuberosity Ischial tuberosity Head of finula Medial condyle of tibia and collateral ligament Tibia Flexes knee; laterally rotates leg; extends hip Flexes knee; medially rotates leg; extends hip Muscles of the Leg Acting on the Leg, Ankle. and Foot MUSCLEORIGININSERTIONACTIONAnterior CompartmentExtensor digitorum longus Extensor hallucis longus Tibialis anterior Fibularis tertiusLateral condyle of tibia and fibula Middle fibula and interosseous membrane Tibia and interosseous membrane Fibula and interosseous membrane Four tendons to phalanges of four lateral toes Distal phalanx of great toe Medial cuneiform and first metatarsal bone First metatarsal bone Extends 4 lateral toes; dorsiflexes & everts foot Extends great toe; dorsiflexes & inverts foot Dorsiflexes and inverts foot Dorsiflexes and everts foot Posterior CompartmentSuperficial •Gastrocnemius •Soleus Deep •Flexor digitorum longus •Flexor hallucis longus •Tibialis posteriorMedial & lateral condyles Fibula and tibia Tibia Fibula Tibia, interosseous membrane, and fibula Calcaneal tendon to calcaneus 4 tendons to distal phalanges distal phalanx of great toe Navicular, cuneiforms, cuboid, and 2nd through 4th metatarsal bones Plantar flexes foot; flexes leg Plantar flexes foot Flexes four lateral toes; plantar flexes and inverts foot Flexes great toe; plantar flexes and inverts foot Plantar flexes and inverts foot Lateral CompartmentFibularis brevis Fibularis longusFibula Fifth metatarsal bone Medial cuneiform and first metatarsal bone Everts and plantar flexes foot
Chapter 7: Muscular System @medtech.files | by MAPB VI. EFFECTS OF AGING ON SKELETAL MUSCLE Aging skeletal muscle is associated with reduced muscle mass, increased time that muscle takes to contract in response to nervous stimuli, less precise muscle control, and a longer recovery period. VII. DISEASES Condition Description Cramps Painful, spastic contractions of a muscle; usually due to a buildup of lactic acid Fibromyalgia Non-life-threatening, chronic, widespread pain in muscles with no known cure; also known as chronic muscle pain syndrome Hypertrophy Enlargement of a muscle due to an increased number of myofibrils, as occurs with increased muscle use Atrophy Decrease in muscle size due to a decreased number of myofilaments; can occur due to disuse of a muscle, as in paralysis Muscular dystrophy Duchenne muscular dystrophy Myotonic muscular dystrophy Group of genetic disorders in which all types of muscle degenerate and atrophy slow motor development with progressive weakness and muscle wasting Muscles are weak and fail to relax following forceful contractions; affects the hands most severely; dominant trait in 1/20,000 births Myasthenia gravis Results from the production of antibodies that bind to acetylcholine receptors, eventually destroying the receptor and thus reducing the number of receptors Tendinitis Inflammation of a tendon or its attachment point, due to overuse of the muscle Fibrosis Scarring of damaged cardiac or skeletal muscle due to deposition of connective tissue Fibrositis Inflammation of fibrous connective tissue, resulting in soreness after prolonged skeletal muscle tension; not progressive
Human Anatomy and Physiology with Pathophysiology CHAPTER 8: NERVOUS SYSTEMChapter 8: Nervous System @medtech.files | by MAPB OUTLINE I.Functions of the Nervous System II.Divisions of the Nervous System III.Cells of the Nervous System A.Neurons B.Glial Cells C.Myelin Sheaths D.Organization of Nervous Tissue IV.Electrical Signals and Neural Pathways A.Resting Membrane Potential B.Action Potentials C.The Synapse D.Reflexes E.Neuronal Pathways V.Spinal Cord VI.Spinal Nerves VII.Brain A.Brainstem B.Cerebellum C.Diencephalon D.Cerebrum VIII.Sensory Functions IX.Somatic Motor Functions X.Other Brain Functions XI.Meninges, Ventricles, and Cerebrospinal Fluid XII.Cranial Nerves XIII.Autonomic Nervous System XIV.Effects of Aging on the Nervous System XV.DiseasesI. FUNCTIONS OF THE NERVOUS SYSTEM 1.Receiving sensory input 2.Integrating information 3.Controlling muscles and glands 4.Maintaining homeostasis 5.Establishing and maintaining mental activity II. DIVISIONS OF THE NERVOUS SYSTEM A. Central nervous system (CNS) •consists of the brain and spinal cord oconnect with each other at the foramen magnum of the skull B. Peripheral nervous system (PNS) •consists of all the nervous tissue outside the CNS, including nerves and ganglia Division of PNS: Sensory division•or afferent division(toward); conducts action potentials from sensory receptors to the CNS •sensory neurons-neurons that transmit action potentials from the periphery to the CNS Motor division•or efferent division (away); conducts action potentials from the CNS to effector organs, such as muscles and glands •motor neurons-neurons that transmit action potentials from the CNS toward the periphery •Motor division can be subdivided into: osomatic nervous system-transmits action potentials from the CNS to skeletal muscles oautonomic nervous system (ANS)-transmits action potentials from the CNS to cardiac muscle, smooth muscle, and glands ‣sympathetic division ‣parasympathetic division Enteric nervous system (ENS) - unique subdivision of PNS; has both sensory and motor neurons contained wholly within the digestive tract; can function w/o input from CNS or other parts of PNS III. CELLS OF THE NERVOUS SYSTEM Two types of cells of nervous system: •neurons •glial cells
Chapter 8: Nervous System @medtech.files | by MAPB A. Neurons ‑or nerve cells ‑receive stimuli, conduct action potentials, and transmit signals to other neurons or effector organs ‑require oxygen and glucose Three Parts •cell body-or soma; contains a single nucleus; processes stimulus •dendrites-are short, often highly branching cytoplasmic extensions that receives stimulus for other neurons or sensory receptors •axons-a single long cell process extending from the neuron cell body; transmits stimulus to a gland, muscle, organ, or other neuron oaxon hillock- cone-shaped projection of the soma; area where the axon leaves the neuron cell body ocollateral axons -another branch of axon attached to the main axon oaxoplasm -cytoplasm of an axon oaxolemma -plasma membrane of axon Types of Neurons According to function: •Sensory neurons(afferent neurons) -conduct action potentials toward the CNS •Motor neurons(efferent neurons) -conduct action potentials away from the CNS toward muscles or glands •Interneurons-conduct action potentials within the CNS from one neuron to another According to structure: •Multipolar neurons-many dendrites and a single axon; most motor neurons and most CNS neurons •Bipolar neurons-have two processes: one dendrite and one axon; found in special sense organs, such as eye and nose •Pseudo-unipolar neurons-have a single process extending from the cell body; appears to have an axon and no dendrites; most sensory neurons B. Glial Cells ‑or neuroglia‑supportive cells of the CNS and PNS; do not conduct action potentials ‑carry out different functions that enhance neuron function and maintain normal conditions within nervous tissue ‑more numerous than neurons; can divide to produce more cells Glial Cells of the CNS •Astrocytes-star-shaped; serve as the major supporting cells in the CNS; provide structural support; regulate neuronal signaling; contribute to blood-brain barrier; help with neural tissue repair oblood-brain barrier-a permeability barrier formed when astrocytes participate with the blood vessel endothelium •Ependymal cells -epithelial-like; line the fluid-filled cavities (ventricles and canals) within the CNS; some form choroid plexuses, which produce CSF•Microglia -act as immune cells of the CNS; small, mobile cells; protect CNS from infection; become phagocytic in response to inflammation•Oligodendrocytes -provide an insulating material that surrounds axons; cell processes form myelin sheaths around axons or enclose unmyelinated axons in the CNSGlial Cells of the PNS •Schwann cells -single cells surrounding axons; form myelin sheaths around axons or enclose unmyelinated axons in the PNS•Satellite cells -surround neuron cell bodies in sensory and autonomic ganglia
Chapter 8: Nervous System @medtech.files | by MAPB OligodendrocyteSchwann cells•produce myelin sheath in CNS•collection of axons: nerve tracts•cell bodies: nuclei •produce myelin sheath in PNS•collection of axons: nerves•cell bodies: ganglionC. Myelin Sheaths •Myelin sheaths-specialized layers that wrap around the axons of some neurons; formed by the cell processes of glial cells; specifically, oligodendrocytes in the CNS and Schwann cells in the PNS omyelinated axons ‑conduct axon potentials more quickly (3-15 meters/sec) than unmyelinated due to nodes of Ranvier ounmyelinated axons •Nodes of Ranvier-gaps in myelin sheath where action potentials develop •Saltatory conduction-jumping of action potentials from one node to another •Multiple sclerosis-disease of myelin sheath that causes loss of muscle function D. Organization of Nervous Tissue Gray matter-consists of groups of neuron cell bodies and their dendrites, where there is very little myelin •cortex-gray matter on the surface of the brain •nuclei-clusters of gray matter located deeper within the brain •ganglion -a cluster of neuron cell bodies in the PNS White matter-consists of bundles of parallel axons with their myelin sheaths, which are whitish in color •nerve tracts-or conduction pathways; formed by white matter of the CNS; propagate action potentials from one area of the CNS to another •nerves-formed by white matter of PNS consisting of bundles of axons and associated connective tissue IV. ELECTRICAL SIGNALS AND NEURAL PATHWAYS A. Resting Membrane Potential •outside of cell is more + (Na+) •inside of cell is more –(K+) The resting membrane potential is generated by three main factors: 1.a higher concentration of K+ immediately inside the cell membrane 2.a higher concentration of Na+ immediately outside the cell membrane 3.greater permeability of the cell membrane to K+ than to Na+ Two basic types of ion channels: •Leak channels-are always open; ions can “leak” across the membrane down their concentration gradient; K+ channels •Gated channels-closed until opened by specific signals; Na+ channels oChemically gated channels-opened by neurotransmitters or other chemicals oVoltage-gated channels-opened by a change in membrane potential sodium-potassium pump - required to maintain the greater concentration of Na+ outside the cell membrane and K+ inside B. Active Potentials ‑electricity that cause depolarization and repolarization ‑change resting membrane potential by activating gated ion channels •local current-movement of Na+; causes the inside of the cell membrane to become positive •depolarization-the inside of the cell membrane become positive; results in local potentialoIf depolarization is not strong enough, the Na+ channels close again, and the local potential disappears without being conducted along the nerve cell membrane. oIf depolarization is large enough, Na+ enters the cell so that the local potential reaches a threshold value. This threshold depolarization causes voltage-gated Na+ channels to open. •hyperpolarization-condition that the charge on the cell membrane briefly becomes more negative than the resting membrane potential
Chapter 8: Nervous System @medtech.files | by MAPB •continuous conduction-action potential is conducted along the entire axon cell membrane •saltatory conduction- action potentials “jump” from one node of Ranvier to the next along the length of the axon C. The Synapse Synapse•Junction where the axon of one neuron interacts with another neuron or with cells of an effector organ •Three major components: oPresynaptic terminal-forms the end of the axon oPostsynaptic terminal-membrane of the dendrite of effector cell oSynaptic cleft-space separating the presynaptic and postsynaptic membranes Neurotransmitters•a chemical substances stored in synaptic vesicles in the presynaptic terminal •acetylcholine (ACh) and norepinephrine-best known neurotransmitters •acetylcholinesterase -an enzyme that breaks down the acetylcholine SubstanceSite of releaseEffectAcetylcholine (ACh) CNS synapses, ANS synapses, and neuromuscular junctions Excitatory or inhibitory Norepinephrine (NE) Selected CNS synapses and some ANS synapses Excitatory Serotonin CNS synapses Generally inhibitory Dopamine Selected CNS synapses and some ANS synapses Excitatory or inhibitory Gamma-aminobutyric acid (GABA) CNS synapses Inhibitory Glycine CNS synapses Inhibitory Endorphins Descending pain pathways Inhibitory D. Reflexes •Reflex-an involuntary reaction in response to a stimulus applied to the periphery and transmitted to the CNS; allow a person to react to stimuli more quickly than is possible if conscious thought is involved •Reflex arc-neuronal pathway by which a reflex occurs; basic functional unit of the nervous system because it is the smallest, simplest pathway capable of receiving a stimulus and yielding a response Five basic components of reflex arc: 1.Stimulus to sensory receptorcreates receptor potential 2.Sends signals (nerve conduction) to sensory/afferent neuron 3.Sent centrally to the CNS (spinal cord) where the interneuronsare located 4.Sends action potential to motor/efferent neuron5.Effectormuscle or gland responds to motor nerve impulses E. Neuronal Pathways •converging pathway-two or more neurons synapse with the same postsynaptic neuron; allows information transmitted in more than one neuronal pathway to converge into a single pathway •diverging pathway-the axon from one neuron divides and synapses with more than one other postsynaptic neuron; allows information transmitted in one neuronal pathway to diverge into two or more pathways summation-allows integration of multiple subthreshold local potentials •spatial summation-occurs when the local potentials originate from different locations on the postsynaptic neuron •temporal summation-occurs when local potentials overlap in time; can occur from a single input that fires rapidly, which allows the resulting local potentials to overlap briefly V. SPINAL CORD ‑part of the CNS; extends from the foramen magnum at the base of the skull to the 2nd lumbar vertebra ‑protected by vertebral column ‑allows movement; if damage, paralysis can occur ‑ends at the conus medullariswhich is the cone-shaped tapered end
Chapter 8: Nervous System @medtech.files | by MAPB •Cauda equina-inferior end of the spinal cord and the spinal nerves exiting; resemble a horse’s tail•White matter-composed of white fibers/myelinated axons; outside of spinal cord •Gray matter-composed of unmyelinated axons; shaped as letter H or butterfly; center of spinal cord •Central canal-fluid-filled space in center of spinal cord •Ventral root-where the spinal nerve rootlets on the ventral aspect combine •Dorsal root-where the spinal nerve rootlets on the dorsal aspect combine •Ganglion -ovoid structures containing cell bodies of neurons and glial cells supported by connective tissue White matter composed of 3 columns: dorsal, ventral, lateral •Ascending tracts-consists of axons that conduct action potential toward brain •Descending tracts-consists of axons that conduct action potentials away from brain Gray matter •Posterior horns-contain axons which synapse with interneurons •Anterior horns-contain somatic neurons •Lateral horns-contain autonomic neurons A. Spinal Cord Reflexes Knee-Jerk Reflex ‑or patellar reflex‑example of stretch reflex •stretch reflex-simplest reflex; occurs when muscles contract in response to a stretching force applied ‑stretching of quadriceps femoris muscle ‑used by clinicians to determine if the higher CNS centers that normally influence this reflex are functional Withdrawal Reflex‑or flexor reflex‑the function is to remove a limb or another body part from a painful stimulus VI. SPINAL NERVES Spinal Nerves‑arise along the spinal cord from the union of the dorsal roots and ventral roots ‑contain axons of both sensory and somatic motor neurons; mixed nerves ‑communicate between the spinal cord and the body; categorized by region of vertebral column from which it emerges ‑31 pairs•cervical (C) C1 –C8 •thoracic (T) T1 –T12 •lumbar (L) L1 –L5 •sacral (S) S1 –S5 •coccygeal (Co) Co dermatome-area of skin supplied with sensory innervation by a pair of spinal nerves plexuses-where neurons of several spinal nerves come together and intermingle coccygeal plexus-originates from S5 and Co; supplies motor innervation to the muscles of the pelvic floor and sensory cutaneous innervation to the skin over the coccyx
Chapter 8: Nervous System @medtech.files | by MAPB Three Major Plexuses: Cervical Plexus -originates from spinal nerves C1 to C4; branches from this plexus innervate several of the muscles attached to the hyoid bone •phrenic nerve-innervates the diaphragm Brachial Plexus -originates from spinal nerves C5 to T1; five major nerves emerge from the brachial plexus to supply the upper limb and shoulder •axillary nerve-innervates two shoulder muscles and the skin over part of the shoulder •radial nerve-innervates all the muscles in the posterior arm and forearm ocrutch paralysis-dysfunction of the radial nerve; paralysis of the posterior arm and forearm muscles and loss of sensation over the back of the forearm and hand •musculocutaneous nerve -innervates the anterior muscles of the arm and the skin over the radial surface of the forearm •ulnar nerve-innervates two anterior forearm muscles and most of the intrinsic hand muscles •median nerve-innervates most of the anterior forearm muscles and some of the intrinsic hand muscles; also innervates the skin over the radial side of the hand Lumbosacral Plexus -originates from spinal nerves L1 to S4; four major nerves exit the lumbosacral plexus to supply the lower limb •obturator nerve-innervates the muscles of the medial thigh and the skin over the same region •femoral nerve-innervates the anterior thigh muscles and the skin over the anterior thigh and medial side of the leg •tibial nerve-innervates the posterior thigh muscles, the anterior and posterior leg muscles, and most of the intrinsic foot muscles; innervates the skin over the sole of the foot •common fibular nerve-innervates the muscles of the lateral thigh and leg and some intrinsic foot muscle •sciatic nerve-tibial and common fibular nerves that are bound together within a connective tissue VII. BRAIN •Part of the CNS; occupies most of the cranial cavity within the skull •Different parts: oBrainstem oCerebellum oDiencephalon oCerebrum •Covered by meninges and CSF A. Brainstem •connects the spinal cord to the rest of the brain •composed of: medulla oblongata, pons, midbrain Medulla Oblongata •most inferior portion; continuous with the spinal cord •it regulates heart rate, blood vessel diameter, breathing, swallowing, vomiting, hiccupping, coughing, sneezing, balance •pyramids-two prominent enlargements that extend the length of the medulla oblongata; involved in conscious control of skeletal muscle Pons •above medulla •functional bridge between the cerebrum and cerebellum •it controls breathing, chewing, salivation, swallowing, relay station between cerebrum and cerebellum Midbrain •above pons; smallest region of the brainstem •it coordinated eye movement, pupil diameter, turning head toward noise •culliculi-four mounds in the dorsal part of midbrain •substantia nigra-black nuclear mass in midbrain which is part of the basal nuclei; involved in regulating general body movements
Chapter 8: Nervous System @medtech.files | by MAPB Reticular formation-group of nuclei that are scattered throughout the brainstem; involved in regulating cyclical motor functions such as respiration, walking, and chewing Reticular activating system-plays a role in arousing and maintaining consciousness and in regulating the sleep-wake cycle B. Cerebellum •translates as “small brain”•located at the postero-inferior portion of the cerebrum and dorsal to the brainstem •controls balance, muscle tone, and fine motor movements •cerebellar peduncles-large connections attached to the brainstem C. Diencephalon •between the brainstem and cerebrum •composed of: thalamus, hypothalamus, epithalamus Thalamus•largest portion of diencephalon •influences moods and detects pain Epithalamus•above thalamus •emotional and visceral response to odors •pineal gland-an endocrine gland that may influence the onset of puberty and may play a role in controlling some long term cycles that are influenced by the light-dark cycle Hypothalamus•below thalamus •controls homeostasis, body temp, thirst, hunger, fear, rage, sexual emotions •infundibulum -funnel-shaped stalk that extends from the floor of the hypothalamus to the pituitary gland •mammillary bodies-externally visible swellings on the posterior portion of the hypothalamus; involved in emotional responses to odors and in memory D. Cerebrum •largest and most prominent part of the brain Divisions: •Left hemisphere-controls the right side of the body, responsible for science and logic •Right hemisphere-controls the left side of the body, responsible for music and art Cerebrum Components •Cerebral cortex-gray matter on the outer surface of the cerebrum; controls thinking, communicating, remembering, understanding, and initiates voluntary movements •Cerebral medulla -white matter of the brain between the cortex and the nuclei •Longitudinal fissure-divides left and right hemisphere •Corpus callosum-mass of white fibers that connects the left and right hemispheres •Gyri-convoluted folds on the cerebral cortex that increases the surface area •Sulci-shallow indentions •Fissure-deep indentations •Central sulcus-separates the frontal and parietal lobe •Lateral fissure -separates the temporal lobe from the rest of the cerebrum •Transverse fissure -separates cerebrum and cerebellum
Chapter 8: Nervous System @medtech.files | by MAPB Lobes of the Cerebrum •Frontal lobe-control of voluntary motor functions, motivation, aggression, mood, and smell •Parietal lobe-principal center for receiving and consciously perceiving most sensory information; touch, pain, temperature, and balance •Occipital lobe-receiving and perceiving visual input •Temporal lobe-involve in smell (olfactory), hearing (auditory), and memory •Insula-fifth lobe, functions for desires, cravings, and addiction VIII. SENSORY FUNCTIONS Ascending Tracts ‑pathways in brain and spinal cord ‑transmit information via action potentials from periphery to brain ‑each tract has limited type of sensory input (temp, touch, pain, etc.) ‑tracts are named that indicated origin and termination ‑made of 2-3 neurons in sequence Pathway Function Spinothalamic Pain, temperature, light touch, pressure, tickle, and itch sensations Dorsal column Proprioception, touch, deep pressure, and vibration Spinocerebellar Proprioception to cerebellum Sensory Areas of Cerebral Cortex •Primary sensory area-where ascending tracts project; where sensations are perceived •Primary somatic sensorycortex -general sensory area; in parietal lobe; sensory input such as pain, pressure, temperature IX. SOMATIC MOTOR FUNCTIONS Motor Areas of Cerebral Cortex •Primary motor cortex-frontal lobe; control voluntary motor movement •Premotor area-frontal lobe; where motor functions are organized before initiation •Prefrontal area-motivation and foresight to plan and initiate movement Descending Tracts ‑project from upper motor neurons in cerebral cortex to lower motor neurons in spinal cord and brainstem ‑control different types of movements Pathway Function Direct Lateral corticospinalAnterior corticospinal Muscle tone and skilled movements, especially of hands Muscle tone and movement of trunk muscles Indirect RubrospinalReticulospinalVestibulospinalTectospinal Movement coordination Posture adjustment, especially during movement Posture and balance Movement in response to visual reflexes Basal Nuclei •group of functionally related nuclei •plan, organize, coordinate motor movements and posture •Two primary nuclei: oCorpus striatum-deep in cerebrum oSubstantia nigra- group of darkly pigmented cells in the midbrain
Chapter 8: Nervous System @medtech.files | by MAPB X. OTHER BRAIN FUNCTIONS Communication Between the Right and Left Hemispheres •Right cerebral hemisphere-receives sensory input from and controls muscular activity in the left half of the body. •Left cerebral hemisphere-receives input from and controls muscles in the right half of the body •Commissures-connections between the two hemispheres •Corpus callosum-a broad band of nerve tracts at the base of the longitudinal fissure Speech ‑mainly in left hemisphere 2 major cortical area: •Sensory speech (Wernicke’s area) -parietal lobe; where words are heard and comprehended•Motor speech (Broca’s area) -frontal lobe; where words are formulated; controls the movement necessary for speech aphasia-absent or defective speech or language comprehension Brain Waves and Consciousness Electroencephalogram (EEG)-monitors brain waves Brainwaves-a summation of the electrical activity of the brain •Alpha waves-observed in a normal person who is awake but in a quiet, resting state with the eyes closed •Beta waves-have a higher frequency than alpha waves and occur during intense mental activity •Delta waves-occur during deep sleep, in infants, and in patients with severe brain disorders •Theta waves-usually observed in children, but they can also occur in adults who are experiencing frustration or who have certain brain disorders Memory •Encoding-brief retention of sensory input received by brain while something is scanned, evaluated, and acted up; also called sensory memory; in temporal lobe; lasts less than a second •Consolidated -data that has been encoded; temporal lobe; short term memory•Storage -long term memory; few minutes or permanently (depends on retrieval)•Retrieval -how often information is used Types Of Memory •Working memory -task-associated memory; information is retained for a few seconds or minute; bits of info (usually 7) •Short-term memory-few minutes to a few days; susceptible to brain trauma, drugs •Long-term memory-can last for a few minutes or permanently; length of time memory is stored may depend on how often it is retrieved and used •Declarative/explicit memory -retention of facts, such as names, dates, and places, as well as related emotional undertones •Procedural memory/reflexive memory -development of motor skills Limbic System and Emotions Limbic System ‑located in deep cortical structures ‑influences long term declarative memory, emotions, visceral response to emotions, motivation and mood ‑responds to olfactory stimulation by initiating response necessary for survival ‑voracious appetite; increase sexual activity; loss of fear and anger response XI. MENINGES, VENTRICLES, AND CEREBROSPINAL FLUID A. Meninges ‑protective wrapping around brain and spinal cord ‑three connective tissue membranes Dura mater-tough, skin-like outermost covering; thickest layer •subdural space-space between the dura mater and the arachnoid mater; space containing a very small amount of serous fluid
Chapter 8: Nervous System @medtech.files | by MAPB Arachnoid mater-deep to the dura mater and is a much thinner layer and appears spidery •Subarachnoid space-space under the arachnoid mater and is filled with CSF Pia mater-thin, vascular membrane adhering to the surface •Epidural space-in vertebral column between dura and vertebra; injection site for epidural anesthesia •Spinal block -to inject anesthetic into the area •Spinal tap-take a sample of cerebrospinal fluid B. Ventricles •cavities in CNS that contain fluid •lateral ventricle-large cavity in each cerebral hemisphere •third ventricle-a smaller, midline cavity located in the center of the diencephalon •fourth ventricle-base of cerebellum; continuous with central canal of spinal cord oconnected to the third ventricle by a narrow canal, called the cerebral aqueductC. Cerebrospinal Fluid (CSF) •bathes the brain and spinal cord, providing a protective cushion around CNS •choroid plexus-produce the CSF •hydrocephalus-accumulation of CSF in the ventricles Flow of CSF 1.Lateral ventricle 2.Third ventricle 3.Cerebral aqueduct/Aqueduct of Sylvius 4.Fourth ventricle 5.Central canal of the spinal cord XII. CRANIAL NERVES •12 pair of cranial nerves •named by roman numerals 2 Categories of Functions •Sensory functions-vision, touch, pain •Motor functionsoSomatic motorcranial nervesinnervate skeletal muscles in the head and neck oParasympatheticcranial nervesinnervate glands, smooth muscle throughout the body, and cardiac muscle of the heart
Chapter 8: Nervous System @medtech.files | by MAPB Cranial Nerves and Their Functions Number Name General Functions* Specific Function I Olfactory S Smell II Optic S Vision III Oculomotor M, P Motor to four of six extrinsic eye muscles and upper eyelid; parasympathetic: constricts pupil, thickens lens IV Trochlear M Motor to one extrinsic eye muscle V Trigeminal S, M Sensory to face and teeth; motor to muscles of mastication (chewing) VI Abducens M Motor to one extrinsic eye muscle VII Facial S, M, P Sensory: taste; motor to muscles of facial expression; parasympathetic to salivary and tear glands VIII Vestibulocochlear S Hearing and balance IX Glossopharyngeal S, M, P Sensory: taste and touch to back of tongue; motor to pharyngeal muscles; parasympathetic to salivary glands X Vagus S, M, P Sensory to pharynx, larynx, and viscera; motor to palate, pharynx, and larynx; parasympathetic to viscera of thorax and abdomen XI Accessory M Motor to two neck and upper back muscles XII Hypoglossal M Motor to tongue muscles *S, sensory; M, somatic motor; P, parasympathetic XIII. AUTONOMIC NERVOUS SYSTEM Divisions oof Autonomic Nervous System 1. Sympathetic•activated during times of stress •part of flight or flight response •prepares you for physical activity by: oincreasing heart rate, blood pressure, and breathing rate osending more blood to skeletal muscles oinhibiting digestive tract 2. Parasympathetic •housekeeper •activated under normal conditions •rest and digest •stimulates involuntary activities of the body at rest •involved in digestion, urine production, and dilation/constriction of pupils, etc. XIV. EFFECTS OF AGING ON THE NERVOUS SYSTEM •In general, sensory and motor functions decline with age. •Mental functions, including memory, may decline with age, but this varies from person to person. XV. DISEASES Condition Description CNS Disorders Encephalitis Inflammation of the brain caused by a virus and less often by bacteria or other agents Meningitis Inflammation of meninges caused by viral or bacterial infection Multiple sclerosis Autoimmune condition; inflammation in brain and spinal cord with demyelination and sclerotic (hard) sheaths results in poor conduction of action potentials Parkinson disease Caused by a lesion in basal nuclei; characterized by muscular rigidity, resting tremor, general lack of movement, and a slow, shuffling gait Alzheimer disease Mental deterioration, or dementia; usually affects older people; involves loss of neurons in cerebral cortex PNS Disorders Herpes Family of diseases characterized by skin lesions due to herpes viruses in sensory ganglia Poliomyelitis Viral infection of the CNS; damages somatic motor neurons, leaving muscles without innervation, and leads to paralysis and atrophy Myasthenia gravis Autoimmune disorder affecting acetylcholine receptors; makes the neuromuscular junction less functional; muscle weakness and increased fatigue lead to paralysis
Human Anatomy and Physiology with Pathophysiology CHAPTER 9: ENDOCRINE SYSTEMChapter 9:Endocrine System @medtech.files | by MAPB OUTLINE I.Principles of Chemical CommunicationII.Functions of the Endocrine System III.Characteristics of the Endocrine System IV.Hormones V.Control of Hormone Secretion VI.Hormone Receptors and Mechanisms of Action VII.Endocrine Glands and Their Hormones A.Pituitary and Hypothalamus B.Thyroid Gland C.Parathyroid Glands D.Adrenal Glands E.Pancreas, Insulin, and Diabetes F.Testes and Ovaries G.Thymus H.Pineal Gland VIII.Other Hormones IX.Effects of Aging on the Endocrine System X.DiseasesI. PRINCIPLES OF CHEMICAL COMMUNICATION Chemical Messengers ‑allows cells to communicate with each other to regulate body activities Classes of Chemical Messenger •Autocrine-secreted by cells in a local area; influences the activity of the same cell or cell type from which it was secreted •Paracrine-produced by a wide variety of tissues and secreted into extracellular fluid; has a localized effect on other tissues •Neurotransmitter-produced by neurons; secreted into a synaptic cleft by presynaptic nerve terminals; travels short distances; influences postsynaptic cells •Endocrine-secreted into the blood by specialized cells; travels some distance to target tissues; results in coordinated regulation of cell function Types of Chemical Signals •Intracellular-produce in one part a cell and move to another part of same cell •Intercellular-released from one cell and bind to receptors on another cell II. FUNCTIONS OF THE ENDOCRINE SYSTEM 1.Metabolism 2.Control of food intake and digestion 3.Tissue development 4.Ion regulation 5.Water balance 6.Heart rate and blood pressure regulation 7.Control of blood glucose and other nutrients 8.Control of reproductive functions 9.Uterine contractions and milk release 10.Immune system regulation III. CHARACTERISTICS OF THE ENDOCRINE SYSTEM Endocrine System •consists of ductless glands that secrete hormones into the interstitial fluid •endo–within; krino–secrete •Endocrine glands-secrete their product directly on bloodstream •Hormones-chemical messengers; derived from Greek word hormone, which means to set into motion •Endocrinology -study of the endocrine system Exocrine glands-have ducts that carry their secretions to the outside of the body, or into a hollow organ
Chapter 9: Endocrine System @medtech.files | by MAPB IV. HORMONES How Does Hormones Work? 1.Hormones are secreted by endocrine glands directly into bloodstream 2.Hormones travel to all parts of body 3.Hormones (key) bind to receptor site (lock) on target tissue 4.Response occurs Chemical Nature of Hormones Lipid-soluble hormones •nonpolar; include steroid hormones, eicosanoids, thyroid hormones, and fatty acid derivative hormones •small molecules that are insoluble in water-based fluids (plasma and blood); attached to binding proteins •Example: LH, FSH, androgens Water-soluble hormones •polar molecule; include protein hormones, peptide hormones, and most amino acid derivative hormones •most common; can be dissolved in blood; circulate as free hormones; delivered directly to their target tissue without attaching to a binding protein •Example: growth hormone, ADH, prolactin, etc. V. CONTROL OF HORMONE SECRETION Stimulation of Hormone Release Control byHumoral Stimuli •Some hormones are secreted in direct response to changes in certain blood-borne chemicals •Ex: blood glucose levels (insulin) Control byNeural Stimuli •Some hormone secretion is due to a stimulus from a neurotransmitter. •Example: epinephrine and fight or flight response •releasing hormones-hormones from hypothalamus Control byHormonal Stimuli •Some hormone secretion is due to a stimulus from another hormone. •tropic hormones-hormones from the anterior pituitary gland; hormones that stimulate the secretion of another hormone Regulation of Hormone Levels in the Blood Negative feedback •the increase in concentration of hormone in the blood will send negative signals to the endocrine gland to slow down or stop its secretion •more commonly observed •self-limiting system Positive feedback •less commonly observed •increase in blood level hormone will further increase of the hormone being released •self-propagated system VI. HORMONE RECEPTORS AND MECHANISMS OF ACTION •Receptor site-location on a cell where hormone binds (lock) •Target tissues-group of cells that respond to specific hormones •Specificity-specific hormones bind to specific receptor sites Classes of Receptors 1.Lipid-soluble hormones bind to nuclear receptors •Nonpolar molecules can freely cross the cell membrane 2.Water-soluble hormones bind to membrane-bound receptors •Polar molecules and cannot pass through the cell membrane VII. ENDOCRINE GLANDS AND THEIR HORMONES A. Pituitary and Hypothalamus Pituitary gland ‑aka hypophysis; extension of hypothalamus; small gland about the size of a pea located in the Sella turcica(sphenoid bone) ‑master glandof the body (produces hormones that control other endocrine organs) Hypothalamus‑an important autonomic nervous system and endocrine control center of the brain located inferior to the thalamus ‑Hypothalamus controls the pituitary gland in two ways: hormonal controland direct innervation
Chapter 9: Endocrine System @medtech.files | by MAPB infundibulum-connects the hypothalamus and the pituitary gland Anterior pituitary•made up of epithelial cells derived from the embryonic oral cavity •synthesizes hormones, whose secretion is under the control of the hypothalamus •hormonal control •hypothalamic-pituitary portal system-capillary beds and veins that transport the releasing and inhibiting hormones Hormones of Anterior Pituitary Growth hormone ‑increases gene expression, breakdown of lipids, and release of fatty acids from cells; increases blood glucose levels ‑stimulates the growth of bones, muscles, and other organs •pituitary dwarfism-a young person suffering from a deficiency of growth hormone remains small, although normally proportioned •giantism-abnormally tall; excess growth hormone is present before bones finish growing in length; exaggerated bone growth occurs •acromegaly-facial features and hands become abnormally large; excess hormone is secreted after growth in bone length is complete; growth continues in bone diameter only Thyroid-stimulating hormone (TSH) •increases thyroid hormone secretion (thyroxine and triiodothyronine) Adrenocorticotropic hormone (ACTH) •increases secretion of glucocorticoid hormones, such as cortisol; increases skin pigmentation at high concentrations •increases the secretion of a hormone from the adrenal cortex called cortisol, also called hydrocortisoneMelanocyte-stimulating hormone (MSH) •increases melanin production in melanocytes to make skin darker in color Luteinizing hormone (LH) or interstitial cell–stimulating hormone (ICSH) •promotes ovulation and progesterone production in ovary; promotes testosterone synthesis and support for sperm cell production in testis Follicle-stimulating hormone (FSH) •promotes follicle maturation and estrogen secretion in ovary; promotes sperm cell production in testis •Gonadotropins -regulate the growth, development, and functions of the gonads (LH AND FSH)Prolactin •stimulates milk production and prolongs progesterone secretion following ovulation and during pregnancy in women; increases sensitivity to LH in males Posterior pituitary•extension of the brain and is composed of nerve cells •regulated by neural input•storage location for two hormones synthesized by special neurons in the hypothalamus •direct innervation Hormones of Posterior Pituitary Antidiuretic hormone (ADH) •aka vasopressin •conserves water; constricts blood vessels •increases water reabsorption in kidney tubules •Diabetes insipidus -low ADH; kidneys to produce large amount of dilute (watery urine); lead to dehydration and thirst
Chapter 9: Endocrine System @medtech.files | by MAPB Oxytocin •increases uterine contractions •increases milk letdown from mammary glands •Pitocin-commercial preparations of oxytocin; given under certain conditions to assist in childbirth and to constrict uterine blood vessels following childbirth B. THYROID GLAND ‑butterfly-shaped located on the anterior aspect of the trachea inferior to the larynx ‑composed of 2 lobes connected by the isthmus‑one of the largest glands and is highly vascular ‑requires iodine to function ‑main function is to produce thyroid hormonesas stimulated by the thyroid stimulating hormone (TSH) •Thyroid follicle -glandular formation where thyroid hormones are synthesized and stored; small spheres with walls composed of simple cuboidal epithelium; filled with the protein thyroglobulinto which thyroid hormones are attached •Colloid-pinkish content of the follicle which contains the thyroid hormones; stored form of hormones •Follicular cells-simple cuboidal epithelium •Parafollicular cells/C cells-network of loose connective tissue between the follicles; secrete the hormone called calcitonin Hormones of Thyroid Gland Thyroid hormones (thyroxine, triiodothyronine) -increase metabolic rates, essential for normal process of growth and maturation •thyroxine (T4)-aka tetraiodothyronine; contains four iodine atoms •triiodothyronine (T3)-contains three iodine atoms Disorders: •goiter–loss of negative feedback will result in excess TSH, causing the thyroid gland to enlarge •hypothyroidism-lack of thyroid hormones; results in cretinism in infants; results in decreased metabolic rate in adults •cretinism-in infants; characterized by mental retardation, short stature, and abnormally formed skeletal structures •myxedema-in adults; accumulation of fluid and other molecules in the subcutaneous tissue of the skin •hyperthyroidism-elevated rate of thyroid hormone secretion; an increased metabolic rate, extreme nervousness, and chronic fatigue •Grave disease-an autoimmune disease that causes hyperthyroidism; occurs when the immune system; produces abnormal proteins that are similar in structure and function to TSH, which overstimulates the thyroid gland •exophthalmia -bulging of the eyesCalcitonin•decreases rate of bone breakdown; prevents large increase in blood Ca2+ levels following a meal; secreted by parafollicular cells C. Parathyroid Gland -embedded in the posterior wall of the thyroid gland •Chief cells-primary producers of PTH; appear denser with larger nucleus •Oxyphil cells-scattered among the chief cells and are considered as back-up hormone producers; have more cytoplasm with an overall lighter appearance Parathyroid hormone-increases rate of bone breakdown by osteoclasts; increases vitamin D synthesis, essential for maintenance of normal blood calcium levels •hyperparathyroidism-abnormally high rate of PTH secretion •hypoparathyroidism-abnormally low rate of PTH secretion If Ca2+ is low, osteoclasts break down bone matrix and less Ca2+ is lost in urine. If Ca2+ is high, osteoclasts don’t break down bone matrix and more Ca2+ is lost in urine.
Chapter 9: Endocrine System @medtech.files | by MAPB D. Adrenal Glands •aka suprarenal gland •2 small glands located superior to each kidney •cone-shaped gland located on top of the kidneys •composed of two layers: adrenal medulla (inner part) and adrenal cortex (outer part) Adrenal medulla Chromaffin cells-makeup the medulla and secrete epinephrine and norepinephrine •Epinephrine-aka adrenaline; principal hormone released from adrenal medulla •NorepinephrineEpinephrine mostly, some norepinephrine •increases cardiac output; increases blood flow to skeletal muscles and heart; increases release of glucose and fatty acids into blood; in general, prepares body for physical activity •fight-or-flight hormonesAdrenal cortex •Zona glomerulosa-outermost region; secretes mineralocorticoids; arranged in balls and loops •Zona fasciculata-secretes glucocorticoids; straight rows •Zona reticularis-innermost layer; secretes androgen Mineralocorticoids (aldosterone) -increase rate of sodium transport into body; increase rate of potassium excretion; secondarily favor water retention •aldosterone-major mineralocorticoids hormone •renin-a protein molecule from the kidney that are released because of low blood pressure; act as enzyme that causes angiotensinogen to be converted to angiotensin I •angiotensin-converting enzyme-a protein that causes angiotensin I to be converted to angiotensin II Glucocorticoids (cortisol) -increase blood nutrient levels; inhibit inflammation and immune response •cortisol-major glucocorticoids hormone; increase lipid and protein breakdown; increase glucose synthesis from amino acids Adrenal androgens -insignificant in males; increase female sexual drive, growth of pubic and axillary hair •hypoadrenalism-failure of adrenal cortex to produce adrenocortical hormones •Addison’s disease-signs and symptoms: hyponatremia, hyperkalemia, sluggishness, weak muscles •hyperadrenalism•Cushing’s syndrome -abnormal secretion of cortisol and androgens; too much intake of steroid; buffalo torso(deposition of fat in the thoracic and upper abdominal region); moon face (edematous face) E. Pancreas, Insulin, and Diabetes •both an exocrine and endocrine gland •long, narrow mass of glandular tissue cradled in the duodenum •consists of pancreatic islets (islets of Langerhans)•Acinar cells-exocrine cells; secrete pancreatic juice/digestive juice called amylase •Islets of Langerhans-endocrine cells; dispersed throughout the exocrine portion of pancreas; 3 types:oalpha cells-secrete glucagon obeta cells-secrete insulin odelta cells-secrete somatostatin Insulin -increases uptake and use of glucose and amino acids; released when blood glucose levels are elevated •satiety center-area of the hypothalamus that controls appetite
Chapter 9: Endocrine System @medtech.files | by MAPB •diabetes mellitus-the body’s inability to regulate blood glucose levels within the normal range otype 1 diabetes mellitus-occurs when too little insulin is secreted from the pancreas otype 2 diabetes mellitus-cause by either too few insulin receptors on target cells or defective receptors on target cells •hyperglycemia-a condition where blood glucose levels become very high •insulin shock-blood glucose become very low because of too much insulin injection or has not eaten after insulin injection Glucagon •increases breakdown of glycogen and release of glucose into the circulatory system; released when blood glucose levels are low Somatostatin •released in response to food intake; inhibits secretion of insulin and glucagon and inhibits gastric tract activity F. Testes and Ovaries Testes Testosterone •aids in sperm cell production, maintenance of functional reproductive organs, secondary sex characteristics, sexual behavior •growth of body hair, voice changes, and male sexual drive Ovaries Estrogens and Progesterone -aid in uterine and mammary gland development and function, external genitalia structure, secondary sex characteristics, sexual behavior, menstrual cycle •estrogen-primary female sex hormone; female reproductive organ development •progesterone-thickens the lining of the uterus to nourish the fertilized egg G. Thymus ‑located in the upper thoracic cavity ‑can only be found in children ‑functions both as an endocrine gland and lymphatic organ ‑sites for the development of T lymphocytes Thymosin•promotes immune system development and function •aids the development of WBC called T cells H. Pineal Gland ‑small, pinecone-shaped structure located superior and posterior to the thalamus of the brain Melatonin•sleep-inducing hormone •inhibits secretion of gonadotropin-releasing hormone, thereby inhibiting reproduction VIII. OTHER HORMONES •Prostaglandins-mediate inflammatory responses; increase uterine contractions and ovulation; widely distributed in tissues of the body; function as intercellular signals •Atrial natriuretic hormone (ANH or ANP)-secreted by right atrium of the heart in response to elevated blood pressure •Erythropoietin-secreted by kidney in response to reduced oxygen levels in the kidney; act on bone marrow to increase the production of RBC •Human chorionic gonadotropin (HCG)-produces by the chorion of the embryo during early development; increases during pregnancy and is the bases of pregnancy test
Chapter 9: Endocrine System @medtech.files | by MAPB IX. EFFECTS OF AGING ON THE ENDOCRINE SYSTEM •Age-related changes include a gradual decrease in oGH in people who do not exercise omelatonin othyroid hormones (slight decrease) oreproductive hormones othymosin •Parathyroid hormones increase if vitamin D and Ca2+ levels decrease. •There is an increase in type 2 diabetes in people with a familial tendency. X. DISEASES Condition Description Diabetes insipidus due to a lack of ADH from the posterior pituitary; results in excessive urination Hashimoto thyroiditis autoimmune disease in which thyroid hormone secretion can be decreased; metabolic rate is decreased, weight gain is possible, and activity levels are depressed Primary hyperparathyroidism 90% of cases due to adenoma of the parathyroid gland; causes blood PTH levels to increase above normal; elevated blood Ca2+ levels, weakened bones and possible muscular weakness Addison disease low levels of aldosterone and cortisol from the adrenal cortex; low blood Na+ levels, low blood pressure, and excessive urination Gestational diabetes develops in pregnant women due to actions of the placental hormone, human placental lactogen (HPL); in some women, HPL overly desensitizes the woman’s insulin receptors; causes elevated blood glucose levels in the mother and, if left untreated, excessive fetal growth
Human Anatomy and Physiology with Pathophysiology CHAPTER 10: BLOODChapter 10: Blood @medtech.files | by MAPB OUTLINE I.Functions of Blood II.Composition of Blood III.Plasma IV.Formed Elements A.Production of Formed Elements B.Red Blood Cells C.White Blood Cells D.Platelets V.Preventing Blood Loss A.Vascular Spasm B.Platelet Plug Formation C.Blood Clotting VI.Blood Grouping A.ABO Blood Group B.Rh Blood Group VII.Diagnostic Blood TestsA.Type and Crossmatch B.Complete Blood Count C.Differential White Blood Count D.Clotting E.Blood Chemistry VIII.DiseasesI. FUNCTIONS OF BLOOD 1.Transport of gases, nutrients, and waste products 2.Transport of processed molecules 3.Transport of regulatory molecules 4.Regulation of pH and osmosis 5.Maintenance of body temperature 6.Protection against foreign substances 7.Clot formation II. COMPOSITION OF BLOOD Blood ‑type of connective tissue that consists of a liquid matrix containing cells and cell fragments ‑O2 content determines color ‑Temperature slightly higher than rest of body Liquid matrix: plasmaCells and cell fragments: formed elements•White blood cells / Leukocytes •Red blood cells / Erythrocytes •Platelets / Thrombocytes Total blood volume: 4-5L(females) and 5-6L(males) III. PLASMA ‑a pale yellow fluid that consists of 91% water, 7% proteins, and 2% other components, such as ions, nutrients, gases, waste products, and regulatory substances Plasma proteins: •albumins-58%; most abundant protein in blood; helps maintain water balance •globulins-38%; helps immune system •fibrinogen-4%; a clotting factor and once activated in blood, it will cause it to solidify, clot, or coagulate Activation of clotting factors results in the conversion of fibrinogen to fibrin, a threadlike protein that forms blood clots Serum-plasma without the clotting factors Composition of PlasmaComponentsFunctions and ExamplesWater Acts as a solvent and suspending medium for blood components Proteins Maintain osmotic pressure (albumin) Destroy foreign substances (antibodies and complement) Transport molecules (albumin and globulins) Form clots (fibrinogen)
Chapter 10: Blood @medtech.files | by MAPB Ions Involved in osmotic pressure (Na+ and Cl-), membrane potentials (Na+ and K+), and acid-base balance (hydrogen, hydroxide, and bicarbonate ions) Nutrients Source of energy and “building blocks” of more complex molecules (glucose, amino acids, triglycerides) Gases Involved in aerobic respiration (oxygen and carbon dioxide) Waste products Breakdown products of protein metabolism (urea and ammonia salts) and red blood cells (bilirubin) Regulatory substances Catalyze chemical reactions (enzymes) and stimulate or inhibit many body functions (hormones) IV. FORMED ELEMENTS A. Production of Formed Elements Hematopoiesis-the process that produces formed elements •All the formed elements of blood are derived from a single population of cells called stem cells, or hemocytoblasts(original cell line) •Fetus: occurs in liver, thymus gland, spleen, lymph nodes, and red bone marrow •After birth: mainly in bone marrow B. Red Blood Cells ‑also called Erythrocytes‑most abundant formed element (95%) ‑biconcave disk; no nucleus (lost during development) ‑contain hemoglobinwhich is responsible for its red color ‑live for about 120 days in males and 110 days in females ‑transport oxygen from the lungs to the various tissues of the body and transport carbon dioxide from the tissues to the lungs Carbonic anhydrase‑found primarily inside red blood cells, catalyzes a reaction that converts carbon dioxide (CO2) and water (H2O) into a hydrogen ion (H+) and a bicarbonate ion (HCO3−)Hemoglobin ‑main component of erythrocytes ‑transports O2 ‑each globin protein is attached to a heme molecule ‑each heme contains one iron atom ‑O2 binds to iron Oxyhemoglobin‑hemoglobin with an O2 attached Production of Erythrocytes 1.Decreased blood O2 levels cause kidneys to increase production of erythropoietin. 2.Erythropoietin stimulates red bone marrow to produce more erythrocytes. 3.Increased erythrocytes cause an increase in blood O2 levels. Fate of Old Erythrocytes and Hemoglobin •Old rbc’s are removed from blood by macrophages in spleen and liver •Hemoglobinis broken down •Globinis broken down into amino acids •Hemoglobin’s iron is recycled•Heme is converted to bilirubin•Bilirubinis taken up by liverand released into small intestine as part of bileC. White Blood Cells ‑also called Leukocytes‑larger than RBC ‑function to: •protect the body against microorganism •remove dead cells and debris by phagocytosis Granulocytes-those with large cytoplasmic granules •Neutrophil •Eosinophil •Basophil Agranulocytes-those with very small cytoplasmic granules that can’t be seen by the light microscope •Lymphocytes -smallest •Monocytes -largest GranulocytesNeutrophils-60-70% -most abundant -remain in blood for 10-12 hours then move to tissues -multi-lobed (2-4) granules that increase during bacterial infection Eosinophil-2-4% -orange to red appearing granulocyte that is found in allergic reactions -two indistinct lobes -reduce inflammation associated with allergies, and worm parasites
Chapter 10: Blood @medtech.files | by MAPB Basophil-0.5-1% -least common of all WBC -with dark blue to dark violet granules -release histamine and heparin Agranulocytes Lymphocytes -20-25% -small agranulocyte that is responsible for antibody reactions -increase during viral infection -several different types (T cells and B cells) Monocytes-3-8% -largest of all WBC -seen in chronic infections and become macrophages when they rich the tissues D. Platelets ‑also called Thrombocytes‑blood clotting cells ‑come from megakaryocytewhich is a giant cell that fragments ‑function is to close and repair wounds by forming platelet plug (or thrombus) V. PREVENTING BLOOD LOSS •When blood vessels are damaged, blood can lead into other tissues and disrupt normal function. •Blood that is lost must be replaced by production of new blood or by a transfusion. A. VascularSpasm‑an immediate but temporary constriction of a blood vessel that results when smooth muscle within the wall of the vessel contracts (ANS, thromboxane, endothelin) B. Platelet Plug Formation Platelet plug-an accumulation of platelets that can seal up a small break in a blood vessel •platelet adhesion-occurs when von Willebrand factor connects exposed collagen to platelets •platelet release reaction-ADP, thromboxanes, and other chemicals are released and activate other platelets •Platelet aggregation-fibrinogen forms bridges between the fibrinogen receptors of numerous platelets, resulting in a platelet plug C. Blood Clotting‑or coagulation ‑blood can be transformed from a liquid to a gel •Clot-network of thread-like proteins called fibrinthat trap blood cells and fluid; depends on clotting factors •Clotting factors-proteins in plasma; only activated following injury; made in liver; require vitamin K Steps in Clot Formation 1.Injury to a blood vessel causes inactive clotting factors to become activated due to exposed connective issue or release of thromboplastin2.Prothrombinase(clotting factor) is formed and acts upon prothrombin 3.Prothrombin is switched to its active form thrombin4.Thrombin activates fibrinogen into its active form fibrin5.Fibrin forms a network that traps blood (clots) Control of Clot Formation •Clots need to be controlled so they don’t spread throughout the body •Anticoagulants-prevent clotting factors from forming clots under normal conditions (Ex: Heparin and antithrombin) •Injury causes enough clotting actors to be activated that anticoagulant can’t work in that area of the body Clot Retraction and Fibrinolysis Clot retraction-condensing a clot; serum in plasma is squeezed out of clot; helps enhance healing Fibrinolysis-process of dissolving clot; plasminogen (plasma protein) breaks down clot (fibrin) •An inactive plasma protein called plasminogenis converted to its active form, plasmin. •Thrombin, other clotting factors activated during clot formation, and tissue plasminogen activator (t-PA)released from surrounding tissues •can stimulate the conversion of plasminogen to plasmin. •Over a few days, plasmin slowly breaks down the fibrin. Streptokinase-a bacterial enzyme, and t-PA, produced through genetic engineering, have been used successfully to dissolve clots
Chapter 10: Blood @medtech.files | by MAPB VI. BLOOD GROUPING •transfusion-transfer of blood or blood components from one individual to another •infusion-introduction of a fluid other than blood, such as a saline or glucose solution, into the blood •transfusion reactions -characterized by clumping or rupture of blood cells and clotting within blood vessels •Antigens-molecules on surface of erythrocytes •Antibodies-proteins in plasma •agglutination-clumping of the cells •hemolysis -rupture of the red blood cells •Blood groups-named according to antigen (ABO) A. ABO Blood Group -used to categorize human blood •donoris the person who gives blood •recipientis the person who receives B. RH Blood Group •Rh positive means you have Rh antigens •95-85% of the population is Rh+ •Antibodies only develop if an Rh- person is exposed to Rh+ blood by transfusion or from mother to fetus Example of Rh Reaction •If mother is Rh- and the fetus is Rh+, the mother can be exposed to Rh+ if fetal blood leaks through placenta and mixes with mother’s blood•First time this occurs mother’s blood produces antibodies against antigens •Any repeated mixing of blood causes a reaction Hemolytic Disease of Newborn ‑occurs when mother produces anti-Rh antibodies that cross placenta and agglutination and hemolysis of fetal erythrocytes occurs ‑can be fatal to fetus ‑prevented if mother is treated with RhoGAM which contains antibodies against Rh antigens VII. DIAGNOSTIC BLOOD TESTS A. Type and Crossmatch •Blood typing-determines the ABO and Rh blood groups of a blood sample •Crossmatch -the donor’s blood cells are mixed with the recipient’s serum, and the donor’s serum is mixed with the recipient’s cellsB. Complete Blood Count -provides information such as RBC count, hemoglobin, hematocrit, and WBC count •Hemoglobin measurement-determines amount of hemoglobin; low hemoglobin indicates anemia oNormal: ‑Male: 14–18 g per 100 mL of blood ‑Female: 12–16 g per 100 mL of blood •Hematocrit-% of total blood volume composed of RBC •White blood count-measures the total number of WBC oNormal: 5000–9000 WBCs per microliter of blood oLeukopenia-low WBC count; caused by radiation, chemotherapy drugs, tumors, vital infections oLeukocytosis-high WBC count; caused by infections and leukemia oLeukemia-cancer of the red marrow characterized by abnormal production of one or more of the white blood cell types, can cause leukocytosis
Chapter 10: Blood @medtech.files | by MAPB C. Differential White Blood Count-determines the % of each 5 kinds of leukocytes •neutrophils (20-70%) •lymphocytes (20-25%) •monocytes (3-8%) •eosinophils (2-4%) •basophils (0.5-1%) D. Clotting •Platelet Count -normal platelet count is 250,000–400,000 platelets per microliter of blood othrombocytopenia-platelet count is greatly reduced, resulting in chronic bleeding through small vessels and capillaries •Prothrombin time measurement-calculates how long it takes for the blood to start clotting, which is normally 9–12 seconds E. Blood Chemistry -measures the composition of materials dissolved or suspended in the plasma CLINICAL IMPACT Anemia-a deficiency of normal hemoglobin in the blood, resulting from a decreased number of red blood cells, a decreased amount of hemoglobin in each red blood cell, or both •Iron-deficiency anemia- insufficient intake or absorption of iron or from excessive iron loss •Folate deficiency-inadequate folate in the diet •Pernicious anemia-caused by inadequate vitamin B12 •Hemorrhagic anemia-results from a loss of blood due to trauma, ulcers, or excessive menstrual bleeding •Hemolytic anemia-occurs when red blood cells rupture or are destroyed at an excessive rate •Thalassemia-a hereditary disease resulting in reduced rates of hemoglobin production •Sickle-cell anemia-a hereditary disease found mostly in people of African descent. The RBC assume a rigid sickle shape and plug up small blood vessels VIII. DISEASES Condition Description ErythrocytosisRelative erythrocytosis overabundance of red blood cells due to decreased blood volume, as may result from dehydration, diuretics, or burnsPrimary erythrocytosis (polycythemia vera) stem cell defect of unknown cause; results in overproduction of red blood cells, granulocytes, and platelets Secondary erythrocytosis overabundance of red blood cells resulting from decreased oxygen supply, as occurs at high altitudes, in chronic obstructive pulmonary disease, or in congestive heart failureClotting DisordersDisseminated intravascular coagulation (DIC) clotting throughout the vascular system, followed by bleeding; may develop when normal regulation of clotting byanticoagulants is overwhelmed, as occurs due to massive tissue damagevon Willebrand disease most common inherited bleeding disorder; platelet plug formation and the contribution of activated platelets to blood clotting are impairedHemophilia genetic disorder in which clotting is abnormal or absent; each of the several types results from deficiency or dysfunction of a clotting factorInfectious Diseases of the Blood Septicemia (blood poisoning) spread of microorganisms and their toxins by the blood; often the result of a medical procedure, such as insertion ofan intravenous tubeMalaria caused by a protozoan introduced into blood by the Anopheles mosquito; symptoms include chills and fever produced by toxins released when the protozoan causes red blood cells to ruptureInfectious mononucleosis caused by Epstein-Barr virus, which infects salivary glands and lymphocytes; symptoms include fever, sore throat, and swollen lymph nodesAcquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV), which infects lymphocytes and suppresses immune system
Human Anatomy and Physiology with Pathophysiology CHAPTER 11: HEARTChapter 11: Heart @medtech.files | by MAPB OUTLINE I.Functions of the Heart II.Size, Form, and Location of the Heart III.Anatomy of the Heart A.Pericardium B.External Anatomy C.Heart Chambers and Internal Anatomy D.Heart Valves E.Route of Blood Flow Through the Heart F.Blood Supply to the Heart IV.Histology of the Heart A.Heart Wall B.Cardiac Muscle V.Electrical Activity of the Heart VI.Cardiac Cycle VII.Heart Sounds VIII.Regulation of Heart Function A.Intrinsic Regulation of the Heart B.Extrinsic Regulation of the Heart IX.Effects of Aging on the Heart X.DiseasesI. FUNCTIONS OF THE HEART 1.Generating blood pressure 2.Routing blood 3.Ensuring one-way blood flow 4.Regulating blood supply Circulation •Pulmonary circulation ‑aka pulmonary loop‑circulation where the blood travels from the heart (right ventricle) → lungs → heart (left atrium) •Systemic Circulation ‑aka systemic loop‑circulation where the blood travels out from the left ventricle into the body and back to the right atrium II. SIZE, FORM, AND LOCATION OF THE HEART •Apex-blunt, rounded point of the heart •Base-the larger, flat part at the opposite end of the heart •The heart is located in the thoracic cavity between the two pleural cavities that surround the lungs. The heart, trachea, esophagus, and associated structures form a midline partition, the mediastinum. •The heart is surrounded by its own cavity, the pericardial cavity. III. ANATOMY OF THE HEART A. Pericardium The pericardium consists of two layers: 1.Fibrous pericardium-outer tough layer 2.Serous pericardium-inner layer consists of flat epithelial cells with a thin layer of connective tissue inner layer and is composed of 2 layers: •Parietal pericardium-outer part of the serous pericardium lining the fibrous pericardium •Visceral pericardium-part that covers the heart; aka epicardiumPericardial cavity- located between the visceral and parietal pericardia, is filled with a thin layer of pericardial fluidproduced by the serous pericardium Pericardial fluid-helps reduce friction as the heart moves within the pericardium B. External Anatomy •Right and left atria-located at the base of the heart •Right and left ventricles-extend from the base of the heart toward the apex •coronary sulcus-extends around the heart, separating the atria from the ventricles •interventricular sulcus-diagonal groove located between the right and left ventricles: anterior and inferior •Superior vena cava and inferior vena cava-carry blood from the body to the right atrium •Four pulmonary veins-carry blood from the lungs to the left atrium •great vessels or great arteries-two arteries that carry blood away from the ventricles of the heart •pulmonary trunk-arising from the right ventricle, splits into the right and left •pulmonary arteries-carry blood to the lungs •aorta-arising from the left ventricle, carries blood to the rest of the body
Chapter 11: Heart @medtech.files | by MAPB Anterior view Posterior view C. Heart Chambers and Internal Anatomy Atrium-reservoir where blood from the veins enter; distinguished because of its location and thin walls •Right atrium -receives deoxygenated blood from the SVC, IVC, and coronary sinus; drains blood into the right ventricle •Left atrium-receives oxygenated blood from four pulmonary veins; drains blood into the left ventricle •interatrial septum-partition that separates the two atria Ventricle -major pumping chambers; eject blood into the arteries and the rest of the body; surrounded by muscular layer •Right ventricle -receives blood from the RA and pumps blood into the pulmonary trunk to be oxygenated •Left ventricle -receives blood from the LA and pumps blood into the aorta; has thicker walls •Interventricular septum -walls that separates the 2 ventricles (separates inside) D. Heart Valves ‑structures that prevent backflow and ensures unidirectional flow of blood Two types: •Atrioventricular valve -located between atrium and ventricle oTricuspid valve-aka right AV valve; has three cusps; between right atrium and right ventricle oBicuspid valve-aka mitral valve; has 2 cusps; between left atrium and left ventricle •Semilunar valve-located between the ventricle and great artery; has semilunar valves oPulmonary semilunar valve -between RV and pulmonary trunk/artery oAortic semilunar valve-between LV and aorta Chordae tendineae -thin, strong, connective tissue strings connected to the cusp and the papillary musclesPapillary muscles-fingerlike projections of the ventricular myocardium where the chordae are attached cardiac skeleton-or fibrous skeleton; a plate of connective tissue consists mainly of fibrous rings that surround the AV and semilunar valves E. Route of Blood Flow Through the Heart
Chapter 11: Heart @medtech.files | by MAPB F. Blood Supply to the Heart Coronary Arteries-supply blood to the wall of the heart; originate from the base of the aorta 1.Left coronary artery -originates on the left side of the aorta; it has three major branches:•anterior interventricular artery-lies in the anterior interventricular sulcus •circumflex artery-extends around the coronary sulcus on the left to the posterior surface of the heart •left marginal artery-extends inferiorly along the lateral wall of the left ventricle from the circumflex artery 2.Right coronary artery-originates on the right side of the aorta •posterior interventricular artery-lies in the posterior interventricular sulcus •right marginal artery-extends inferiorly along the lateral wall of the right ventricle Cardiac Veins-drain blood from the cardiac muscle; most of them drain blood into the coronary sinus •coronary sinus-a large vein located within the coronary sulcus on the posterior aspect of the heart IV. HISTOLOGY OF THE HEART A. Heart Wall •Epicardium-aka visceral pericardium; a thin, serous membrane forming the smooth outer surface of the heart •Myocardium-middle layer composed of cardiac muscle cells and is responsible for contraction of the heart chambers •Endocardium- smooth inner surface of the heart chambers; consists of simple squamous epithelium trabeculae carneae- ridges and columns of cardiac muscle B. Cardiac Muscle •Cardiac muscle cells-elongated, branching cells that contain one, or occasionally two, centrally located nuclei •intercalated disks -allow action potentials to pass from one cardiac muscle cell to the next•gap junctions -specialized cell membrane structures in the intercalated disks; allow cytoplasm to flow freely between cells V. ELECTRICAL ACTIVITY OF THE HEART A. Action Potentials in Cardiac Muscle Skeletal Muscle 1.Depolarization phase •Na+ channels open. •K+ channels begin to open. 2.Repolarization phase •Na+ channels close. •K+ channels continue to open, causing repolarization. •K+ channels close at the end of repolarization and return the membrane potential to its resting value. 3.Refractory period effect on tension •Maximum tension is obtained after the refractory period is completed, allowing for increased tension with additional stimulation. Cardiac Muscle 1.Depolarization phase •Na+ channels open. •Ca2+ channels open. 2.Plateau phase •Na+ channels close. •Some K+ channels open, causing repolarization. •Ca2+ channels are open, producing the plateau by slowing further repolarization. 3.Repolarization phase •Ca2+ channels close. •Many K+ channels open. 4.Refractory period effect on tension •Cardiac muscle contracts and relaxes almost completely during the refractory period. B. Conduction System of the Heart •sinoatrial (SA) node-functions as the heart’s pacemaker; is located in the superior wall of the right atrium and initiates the contraction of the heart •atrioventricular (AV) node-located in the lower portion of the right atrium
Chapter 11: Heart @medtech.files | by MAPB •atrioventricular (AV) bundle-a bundle of specialized cardiac muscle; divides into left and right bundle branches •Purkinje fibers-small bundles; pass to the apex of the heart and then extend to the cardiac muscle of the ventricle walls •ectopic beat-result when action potentials originate in an area of the heart other than the SA node •fibrillation -very small portions of the heart to contract rapidly and independently of all other areas C. Electrocardiogram •a record of electrical events within the heart •can be used to detect abnormal heart rates or rhythms, abnormal conduction pathways, hypertrophy or atrophy of the heart, and the approximate location of damaged cardiac muscle. •A normal ECG consists of: oP wave(atrial depolarization) oQRS complex(ventricular depolarization) oT wave(ventricular repolarization) •PQ interval-commonly called the PR interval;atria contract and begin to relax; at the end, ventricles begin to depolarize •QT interval-extends from the beginning of QRS complex to the end of T wave; represents the length of time required for ventricular depolarization and repolarization Abnormal Heart Rhythms Condition Symptoms Tachycardia Heart rate in excess of 100 bpm Bradycardia Heart rate less than 60 bpm Sinus arrhythmia Heart rate varies as much as 5% during respiratory cycle and up to 30% during deep respiration Paroxysmal atrial tachycardia Sudden increase in heart rate to 150–250 bpm for a few seconds or even for several hours; P waves precede every QRS complex; P wave is inverted and superimposed on T wave Atrial flutter As many as 300 P waves/min and 125 QRS complexes/min; resulting in two or three P waves (atrial contractions) for every QRS complex (ventricular contraction) Atrial fibrillation No P waves, normal QRS and T waves, irregular timing; ventricles are constantly stimulated by atria; reduced ventricle filling; increased chance of fibrillation Ventricular tachycardia Frequently causes fibrillation VI. CARDIAC CYCLE -refers to the repetitive pumping process that begins with the onset of cardiac muscle contraction and ends with the beginning of the next contraction •atrial systole-contraction of the two atria •ventricular systole-contraction of the two ventricles •atrial diastole-relaxation of the two atria •ventricular diastole-relaxation of the two ventricles 1.During atrial systole, the atria contract and complete filling of the ventricles. 2.During ventricular systole, the AV valves close, pressure increases in the ventricles, the semilunar valves are forced open, and blood flows into the aorta and pulmonary trunk. 3.At the beginning of ventricular diastole, pressure in the ventricles decreases. The semilunar valves close to prevent backflow of blood from the aorta and pulmonary trunk into the ventricles. 4.When the pressure in the ventricles is low enough, the AV valves open, and blood flows from the atria into the ventricles. VII. HEART SOUNDS •Stethoscope- was originally developed to listen to the sounds of the lungs and heart and is now used to listen to other sounds of the body as well •Two main heart sounds: olubb-first sound; has a lower pitch than the 2nd; results from closure of the AV valves odupp-second heart sound; closure of the semilunar valves
Chapter 11: Heart @medtech.files | by MAPB •Incompetent valve- a heart valve does not close completely •murmurs-abnormal heart sounds; usually a result of faulty valves •stenosed-when the opening of a valve is narrowed VIII. REGULATION OF HEART FUNCTION •Cardiac output-volume of blood pumped by either ventricle per minute •Stroke volume-volume of blood pumped per ventricle each time the heart contracts •Heart rate-beats per minute; number of times the heart contracts each minute CO(mL/min) = SV(mL/beat) x HR(beats/min) •Under resting conditions: oheart rate = approximately 72 beats/min ostroke volume = approximately 70 mL/beat. ocardiac output = slightly more than 5 L/min •During exercise of nonathlete: oheart rate = can increase to 190 bpm ostroke volume = can increase to 115 mL/beat ocardiac output = approximately 22 L/min A. Intrinsic Regulation of the Heart •Intrinsic regulation-refers to mechanisms contained within the heart itself •Preload-the degree to which the ventricular walls are stretched at the end of diastole •Venous return-amount of blood that returns to the heart •Starling’s law of the heart-relationship between preload and stroke volume •Afterload-pressure against which the ventricles must pump blood B. Extrinsic Regulation of the Heart •Extrinsic regulation-refers to mechanisms external to the heart, such as either nervous or chemical regulation •Baroreceptor reflex- mechanism of the nervous system that detects changes in blood pressure. •Baroreceptors-stretch receptors that monitor blood pressure in the aorta and in the wall of the internal carotid arteries •Cardioregulatory center-receives and integrates action potentials from the baroreceptors; controls the action potential frequency in sympathetic and parasympathetic nerve fibers CLINICAL IMPACT Heart Medications •Digitalis-an extract of the foxglove plant, slows and strengthens contractions of the heart muscle •Nitroglycerin -causes dilation of allthe veins and arteries without increasingheart rate or stroke volume •Beta-adrenergic -blocking agents-decrease the rate and strength of cardiac muscle contractions, thus reducing the heart’s O2 demand•Calcium channel blockers-reduce the rate at which Ca2+ diffuses into cardiac and smooth muscle cells •Anticoagulants-prevent clot formation in people whose heart valves or blood vessels have been damaged or in those who have had a myocardial infarction Instruments •Artificial pacemaker-an instrument placed beneath the skin that is equipped with an electrode extending to the heart Surgical Procedures •Heart valve replacement-a surgical procedure performed on patients whose valves are deformed and scarred from a condition such as endocarditis •Heart transplant-possible when the immune characteristics of a donor and a recipient are closely matched •Artificial hearts-have been used on an experimental basis to extend the life of an individual until an acceptable transplant can be found to replace the heart permanently IX. EFFECTS OF AGING ON THE HEART •By age 70, cardiac output has often decreased by one-third. •Hypertrophy of the left ventricle can cause pulmonary edema. •Decrease in the maximum heart rate of 30–60% by age 85 leads to decreased cardiac output. •The aortic semilunar valve can become stenotic or incompetent. •Coronary artery disease and congestive heart failure can develop. •Aerobic exercise improves the functional capacity of the heart at all ages.
Chapter 11: Heart @medtech.files | by MAPB X. DISEASES Condition Description Inflammation of Heart Tissue Endocarditis inflammation of the endocardium; affects the valves more severely than other areas of the endocardiumCardiomyopathy disease of the myocardium of unknown cause or occurring secondarily to other disease; results in weakened cardiac muscle, causing all chambers of the heart to enlargeRheumatic heart disease results from a streptococcal infection in young people; toxin produced by the bacteria can cause rheumatic fever several weeks after the infection that can result in rheumatic endocarditisReduced Blood Flow to Cardiac Muscle Coronary heart disease reduces the amount of blood the coronary arteries can deliver to the myocardiumCoronary thrombosis formation of blood clot in a coronary arteryCongenital Heart Diseases (Occur at Birth) Septal defect hole in the septum between the left and right sides of the heart, allowing blood to flow from one side of the heart to the other Patent ductus arteriosus ductus arteriosus fails to close after birth, allowing blood to flow from the aorta to the pulmonary trunk under a higher pressure, which damages the lungs
Human Anatomy and Physiology with Pathophysiology CHAPTER 12: BLOOD VESSELS AND CIRCULATION Chapter 12: Blood Vessels and Circulation @medtech.files | by MAPB OUTLINE I.Functions of the Circulatory SystemII.General Features of Blood Vessel Structure A.Arteries B.Capillaries C.Veins III.Blood Vessels of the Pulmonary Circulation IV.Blood Vessels of the Systemic Circulation: Arteries V.Blood Vessels of the Systemic Circulation: Veins I. FUNCTIONS OF THE CIRCULATORY SYSTEM 1.Carries blood. 2.Exchanges nutrients, waste products, and gases with tissues. 3.Transports substances. 4.Helps regulate blood pressure. 5.Directs blood flow to the tissues. Blood vessels outside the heart are divided into: •pulmonary vessels-transport blood from the right ventricle of the heart through the lungs and back to the left atrium •systemic vessels-transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium II. GENERAL FEATURES OF BLOOD VESSEL STRUCTURE •Arteries -blood vessels that conduct blood away from the heart; usually carry oxygenated blood•Arterioles-small artery that leads to a capillary •Veins -blood vessels that brings blood back to the heart; usually carry deoxygenated blood•Venules-small vein that leads to a capillary •Capillaries -small network of vessels where air exchange happens Tunics: •tunica intima-innermost layer, consists of an endothelium composed of simple squamous epithelial cells •tunica media-middle layer, consists of smooth muscle cells arranged circularly around the blood vessel •tunica adventitia-composed of dense connective tissue adjacent to the tunica media; becomes loose connective tissue toward the outer portion A. Arteries •Elastic arteries othe largest-diameter arteries and have the thickest walls ogreater proportion of their walls is composed of elastic tissue, and a smaller proportion is smooth muscle oexamples: aorta and pulmonary trunk •Muscular arteries oinclude medium-sized and small arteries owalls are relatively thick compared to their diameter omost of the wall’s thickness results from smooth muscle cells of the tunica media ofrequently called distributing arteries•Arterioles otransport blood from small arteries to capillaries osmallest arteries in which the three tunics can be identified
Chapter 12: Blood Vessels and Circulation @medtech.files | by MAPB B. Capillaries •branch of to form networks •regulated by smooth muscle cells called precapillary sphincters•capillary walls consist of endothelium, which is a layer of simple squamous epithelium C. Veins •Venules ohave a diameter slightly larger than that of capillaries •Small veins oslightly larger in diameter than venules oall three tunics are present •Medium-sized veinsocollect blood from small veins and deliver it to large veins ohave three thin but distinctive tunics •Large veins oalso have three thin but distinctive tunics valves-ensure that blood flows toward the heart but not in the opposite direction III. BLOOD VESSELS OF THE PULMONARY CIRCULATION •pulmonary trunk -branches into right and left pulmonary arteries •pulmonary arteries-extend to the right and left lungs; carry deoxygenated blood to the pulmonary capillaries in the lungs •pulmonary veins(four; two from each lung) -exit the lungs and carry oxygenated blood to the left atrium CLINICAL IMPACT Varicose veins -result when the veins of the lower limbs become so dilated that the cusps of the valves no longer overlap to prevent the backflow of blood Thromboses-occurs when blood clots block veins Phlebitis-inflammation of veins Gangrene -death of body tissue due to a lack of blood flow or a serious bacterial infection IV. BLOOD VESSELS OF THE SYSTEMIC CIRCULATION: ARTERIES A. Aorta Aorta-largest artery; originates from the left ventricle Divisions of aorta: •Ascending aorta-from the left ventricles, it goes upward; where coronary arteriesbranch off •Aortic arch-bend of the aorta •Descending aorta-longest part of the aorta; extends through the thorax and abdomen to the upper margin of the pelvis oThoracic aorta-portion of the aorta in the thorax oAbdominal aorta-part of the descending aorta within the abdomen
Chapter 12: Blood Vessels and Circulation @medtech.files | by MAPB B. Arteries of the Head and Neck •Brachiocephalicartery-1st branch from aortic arch oRight common carotid artery-medial branch of the brachiocephalic artery; transports blood to the right side of the head and neck oRight subclavian artery-lateral branch of the brachiocephalic artery; transports blood to the right upper limb •Left common carotid artery-2nd branch of aortic arch; transports blood to the left side of the head and neck •Left subclavian artery-3rd branch of aortic arch; transports blood to the left upper limb •Internal and External Carotid Artery-branches of common carotid artery oInternal carotid artery-enter the brain to become circle of Willis•Circle of Willis-circular system of arteries around the brain’s base which keeps the brain oxygenatedC. Arteries of the Upper Limbs •Axillary artery-continuation of the subclavian artery inferior to the clavicle •Brachialartery-continuation of the axillary artery in the upper arm •Ulnar artery-medial branch of the brachial artery •Radial artery-lateral branch of the brachial artery D. Thoracic Aorta and Its Branches •Thoracic aorta oVisceral arteriessupply the thoracic organs oParietal arteriessupply the thoracic wall •Intercostal artery-provide blood to the intercostal muscles •Phrenic artery-provide blood to the diaphragm E. Abdominal Aorta and Its Branches •Visceral arteries Unpaired: oCeliacartery-to the stomach, pancreas, liver oSuperiormesenteric artery-small and proximal large intestine
Chapter 12: Blood Vessels and Circulation @medtech.files | by MAPB oInferior mesenteric artery-distal large intestine Paired: oRenal artery-to the kidneys oSuprarenal artery-to the adrenals oGonadalartery-testicular and ovarian •Parietal arteries oinferior phrenic arteries -supply the diaphragm olumbar arteries-supply the lumbarvertebrae and back muscles omedian sacral artery-suppliesthe inferior vertebraeF. Arteries od the Pelvis •Common iliac-goes to the lower extremity oInternal iliac-medial branch of common iliac; provides blood to the pelvic organs oExternal iliac-lateral branch of common iliac; goes down to the lower limb G. Arteries of the Lower limbs •Femoralartery-from external iliac and supplies the thigh •Popliteal artery-from femoral and supplies the posterior knee •Anterior and posterior tibialartery-from femoral and supplies shin area •Dorsalis pedis artery -from the anterior tibial •Fibular artery -aka peroneal artery; from posterior tibial artery; supplies the lateral ed and foot V. BLOOD VESSELS OF THE SYSTEMIC CIRCULATION: VEINS •Superior vena cava-returns blood from the head, neck, thorax, and upper limbs to the right atrium of the heart •Inferior vena cava-returns blood from the abdomen, pelvis, and lower limbs to the right atrium A. Veins of the Head and Neck •Brachiocephalic vein-drains into the SVC •Subclavian vein-lateral branch which drains into the brachiocephalic •Internal jugular vein-medial branch which drains into the brachiocephalic •External jugularvein-external vein of the neck and is the lateral branch which drains into subclavian B. Veins of the Upper Limbs •Axillary vein-medial branch which drains into the subclavian •Brachial vein-superficial vein which drains into the axillary
Chapter 12: Blood Vessels and Circulation @medtech.files | by MAPB •Cephalic vein-lateral branch which drains into the subclavian •Basilic vein-becomes the axillary vein; major superficial veins •Median cubital vein-usually connects the cephalic vein or its tributarieswith the basilic vein*Subclavian vein receives blood from three areas: external jugular vein, axillary vein, and cephalic vein C. Veins of the Thorax •Azygos vein-only found on the left side of the body; unpaired branch which drains into the SVC *SVC receives blood from two areas: brachiocephalic vein and azygos vein •Hemiazygos vein -2 sets of multiple veins that empty into the azygos •Intercostal vein -drains into azygos (left) and hemiazygos (right) D. Veins of the Abdomen and Pelvis •Common iliac vein-2 branches that join together to become the IVC; receives blood from lower extremities and brings it back to IVC •Internal iliac vein-2 branches that join together to become the IVC; drains blood from the pelvic area and brings it back to IVC Pelvic area → internal iliac → common iliac •Portal system-a system of blood vessels that begins and ends with capillary beds and has no pumping mechanism oInferior mesenteric vein-empties into the splenic vein oSplenic vein-carries blood from the spleen and pancreas oHepatic portal vein-formed by splenic and superior mesenteric vein; enters the liver oHepatic vein-drains blood from liver into IVC •Renal vein -kidney to IVC •Suprarenal veins-drain the adrenal glands •Gonadal vein-gonads to IVC E. Veins of the Lower Limbs •External iliac vein-receives all the blood from lower extremities; drains blood into the common iliac •Femoral vein-major lateral branch into the external iliac •Great saphenous vein -major medial branch into the external iliac•Popliteal vein -drains the posterior knee and drains into the femoral•Small saphenous -lateral branch draining to the popliteal•Anterior/Posterior Tibial -draining to the popliteal
Human Anatomy and Physiology with Pathophysiology CHAPTER 13: LYMPHATIC SYSTEM AND IMMUNITYChapter 13: Lymphatic System and Immunity @medtech.files | by MAPB OUTLINE I.Functions of the Lymphatic System II.Anatomy of the Lymphatic System A.Lymphatic Capillaries and Vessels B.Lymphatic Organs C.Overview of the Lymphatic System III.Immunity IV.Innate Immunity A.Physical Barriers B.Chemical Mediators C.White Blood Cells D.Inflammatory Response V.Adaptive Immunity A.Origin and Development of Lymphocytes B.Activation and Multiplication of Lymphocytes C.Antibody-Mediated Immunity D.Cell-Mediated Immunity VI.Acquired Immunity VII.Overview of Immune Interactions VIII.Immunotherapy IX.Effects of Aging on the Lymphatic System and Immunity X.DiseasesI. FUNCTIONS OF THR LYMPHATIC SYSTEM 1.Fluid balance 2.Lipid absorption 3.Defense pathogen -any substance or microorganism that causes disease or damage to the tissues of the body II. ANATOMY OF THE LYMHATIC SYSTEM A. Lymphatic Capillaries and Vessels Lymphatic capillaries‑tiny, closed-ended vessels consisting of simple squamous epithelium ‑more permeable than blood capillaries because they lack a basement membrane, and fluid moves easily into them ‑joins to form larger lymphatic vessels Lymphatic vessels‑resemble small veins ‑have a beaded appearance because they have one-way valves that are similar to the valves of veins Three factors cause compression of the lymphatic vessels: 1.contraction of surrounding skeletal muscle during activity 2.contraction of smooth muscle in the lymphatic vessel wall 3.pressure changes in the thorax during breathing •thoracic duct(uncolored area) -where lymphatic vessels from the rest of the body enters; empties into the left subclavian vein •right lymphatic duct(darkened area) --lymphatic vessels from the right upper limb and the right half of the head, neck, and chest; empties into the right subclavian vein B. Lymphatic Organs •include the tonsils, the lymph nodes, the spleen, and the thymus •Lymphatic tissue-characterized by housing many lymphocytes and other defense cells, such as macrophages
Chapter 13: Lymphatic System and Immunity @medtech.files | by MAPB Tonsils ‑form a protective ring of lymphatic tissue around the openings between the nasal and oral cavities and the pharynx Three groups of tonsils: •palatine tonsils-located on each side of the posterior opening of the oral cavity; these are the ones usually referred to as “the tonsils.•pharyngeal tonsil-located near the internal opening of the nasal cavity oadenoid/s-when the pharyngeal tonsil is enlarged •lingual tonsil-located on the posterior surface of the tongue tonsillectomy-removal of the pharyngeal tonsils adenoidectomy-removal of the palatine tonsil Lymph Nodes ‑rounded structures, varying from the size of a small seed to that of a shelled almond •Capsule-a dense connective tissue that surrounds each lymph node •Trabeculae-extensions of the capsule; subdivide a lymph node into compartments containing lymphatic tissue and lymphatic sinuses •Lymphatic nodules-lymphocytes and other cells that can form dense aggregations of tissue •Lymphatic sinuses-spaces between the lymphatic tissue that contain macrophages on a network of fibers •Germinal centers-lymphatic nodules containing the rapidly dividing lymphocytes; sites of lymphocyte production Three superficial aggregations of lymph nodes: •inguinal nodes in the groin •axillary nodes in the axilla •the cervical nodes in the neck Functions: •activate the immune system •remove pathogens from the lymph through the action of macrophages Spleen ‑roughly the size of a clenched fist and is located in the left, superior corner of the abdominal cavity ‑filters blood instead of lymph ‑blood reservoir ‑has an outer capsuleof dense connective tissue and a small amount of smooth muscle •Trabeculae-divide the spleen into small, interconnected compartments containing two specialized types of lymphatic tissue: owhite pulp-lymphatic tissue surrounding the arteries within the spleen ored pulp-associated with the veins Splenectomy-removal of the spleen Thymus ‑a bilobed gland roughly triangular in shape ‑located in the superior mediastinum ‑site for the maturation of a class of lymphocytes calledT cells‑surrounded by a thin connective tissue capsule •trabeculae-divide each lobe into lobules •cortex-where lymphocytes are numerous and form dark-staining areas •medulla-lighter-staining, central portion of the lobules; fewer lymphocytes
Chapter 13: Lymphatic System and Immunity @medtech.files | by MAPB C. Overview of the Lymphatic System 1.Lymphatic capillariesremove fluid from tissues. The fluid becomes lymph. 2.Lymph flows through lymphatic vessels, which have valves that prevent the backflow of lymph. 3.Lymph nodesfilter lymph and are sites where lymphocytes respond to infections. 4.Lymph enters the thoracic ductor the right lymphatic duct. 5.Lymph enters the blood. 6.Lactealsin the small intestine absorb lipids, which enter the thoracic duct. 7.Chyle, which is lymph containing lipids, enters the blood. 8.The spleenfilters blood and is a site where lymphocytes respond to infections. 9.Lymphocytes(pre-B and pre-T cells) originate from stem cells in the red bone marrow. The pre-B cellsbecome mature B cells in the red bone marrow and are released into the blood. The pre-T cellsenter the blood and migrate to the thymus. 10.The thymusis where pre-T cells derived from red bone marrow increase in number and become mature T cells that are released into the blood. 11.B cells and T cells from the blood enter and populate all lymphatic tissues. These lymphocytes can remain in tissues or pass through them and return to the blood. B cells and T cells can also respond to infections by dividing and increasing in number. Some of the newly formed cells enter the blood and circulate to other tissues. III. IMMUNITY Immunity‑the ability to resist damage from pathogens, such as microorganisms; harmful chemicals, such as toxins released by microorganisms; and internal threats, such as cancer cells Characterized into two systems: •innate immunity(nonspecific resistance)- body recognizes and destroys certain pathogens, but the response to them is the same each time the body is exposed •adaptive immunity (specific immunity) -body recognizes and destroys pathogens, but the response to them improves each time the pathogen is encountered ospecificity-the ability of adaptive immunity to recognize a particular substance omemory-the ability of adaptive immunity to “remember” previous encounters with a particular substance IV. INNATE IMMUNITY A. Physical Barriers ‑prevent pathogens and chemicals from entering the body in two ways: 1.the skin and mucous membranes form barriers that prevent their entry 2.tears, saliva, and urine wash these substances from body surfaces B. Chemical Mediators ‑molecules responsible for many aspects of innate immunity. ‑some chemicals on the surface of cells destroy pathogens or prevent their entry into the cells •Complement-a group of more than 20 proteins found in plasma; can be activated by combining with foreign substances or antibodies; once activated, it can promote inflammation, phagocytosis, and lyse (rupture) bacterial cells •Interferons-are proteins that protect the body against viral infections C. White Blood Cells ‑most important cellular components of immunity ‑produced in red bone marrow and lymphatic tissue and released into the blood chemotaxis -movement of WBC toward chemicals such as complement, leukotrienes, kinins, and histamine Phagocytic Cells Phagocytosis-ingestion and destruction of particles by cells called phagocytes •Neutrophils-small phagocytic WBC; usually the first WBC to enter infected tissues from the blood in large numbers oPus-an accumulation of fluid, dead neutrophils, and other cells at a site of infection •Macrophages-are monocytes that leave the blood, enter tissues, and enlarge about fivefold omononuclear phagocytic system-formed by monocytes and macrophages because they are phagocytes with a single, unlobed nucleus odust cells-lungs oKupffer cells-liver omicroglia-CNS
Chapter 13: Lymphatic System and Immunity @medtech.files | by MAPB Cells of Inflammation •Basophils-derived from red bone marrow; motile WBCs that can leave the blood and enter infected tissues •Mast cells-derived from red bone marrow, are nonmotile cells in connective tissue, especially near capillaries •Eosinophils-participate in inflammation associated with allergies and asthma Natural Killer Cells ‑a type of lymphocyte produced in red bone marrow, and they account for up to 15% of lymphocytes ‑recognize classes of cells, such as tumor cells or virus infected cells, in general, rather than specific tumor cells or cells infected by a specific virus ‑do not exhibit memory response D. Inflammatory Response Bacteria cause tissue damage that stimulates the release or activation of chemical mediators, such as histamine, prostaglandins, leukotrienes, complement, and kinins. •Local inflammation-an inflammatory response confined to a specific area of the body •Systemic inflammation-an inflammatory response that is generally distributed throughout the body oPyrogens-chemicals released by microorganisms, neutrophils, and other cells, stimulate fever production V. ADAPTIVE IMMUNITY Antigens-substances that stimulate adaptive immune responses; can be divided into two groups: •Foreign antigens-introduced from outside the body (bacteria and viruses) •Self-antigens-molecules the body produces to stimulate an immune system response oAutoimmune disease-results when self-antigens stimulate unwanted destruction of normal tissue Adaptive immunity can be divided into: •Antibody-mediated immunity-involves a group of lymphocytes called B cells and proteins called antibodies, which are found in the plasma oAntibodies -produced by plasma cells,which are derived from the B cells •Cell-mediated immunity-involves the actions of a second type of lymphocyte, called T cellsocytotoxic T cells-produce the effects of cell-mediated immunity ohelper T cellscan promote or inhibit the activities of both antibody-mediated immunity and cell-mediated immunity A. Origin and Development of Lymphocytes •Both B cells and T cells originate from stem cellsin red bone marrow. •B cellsare processed from pre-B cells in the red marrow. •T cellsare processed from pre-T cells in the thymus. •Both B cells and T cells circulate to other lymphatic tissues, such as lymph nodes. •clones-small groups of identical B cells or T cells; form during embryonic development B. Activation and Multiplication of Lymphocytes Antigen Recognition Antigen receptors-cell membrane proteins on the surfaces of lymphocytes •B-cell receptors-antigen receptors on B cells •T-cell receptors-antigen receptors on T cellsMajor histocompatibility complex (MHC) molecules-are glycoproteins that have binding sites for antigens •MHC class I molecules -found on the membranes of most nucleated cells •MHC class II molecules-found on the membranes of antigen-presentingcells, B lymphocytes, and other defense cellsLymphocyte Proliferation -important process that generates the needed defense cells to protect the body Proliferation of Helper T Cells 1.Antigen-presenting cells, such as macrophages, phagocytize, process, and display antigens on the cell’s surface. 2.The antigens are bound to MHC class II molecules, which present the processed antigen to the T-cell receptor of the helper T cell. 3.Costimulationresults from interleukin-1, secreted by the macrophage, and the CD4 glycoprotein of the helper T cell. 4.Interleukin-1stimulates the helper T cell to secrete interleukin-2and to produce interleukin-2 receptors.
Chapter 13: Lymphatic System and Immunity @medtech.files | by MAPB 5.The helper T cellstimulates itself to divide when interleukin-2 binds to interleukin-2 receptors. 6.The “daughter” helper T cells resulting from this division can be stimulated to divide again if they are exposed to the same antigen that stimulated the “parent” helper T cell. This greatly increases the number of helper T cells. 7.The increased number of helper T cells can facilitate the activation of B cells or effector T cells. Proliferation of B Cells 1.Before a B cell can be activated by a helper T cell, the B cell must phagocytize and process the same antigen that activated the helper T cell. The antigen binds to a B-cell receptor, and both the receptor and the antigen are taken into the cell by endocytosis. 2.The B cell uses an MHC class II moleculeto present the processedantigen to the helper T cell. 3.The T-cell receptor binds to the MHC class II/antigen complex. 4.There is costimulation of the B cell by CD4 and other surface molecules. 5.There is costimulation by interleukins (cytokines) released from the helper T cell. 6.The B cell divides, the resulting daughter cells divide, and so on, eventually producing many cells that recognize the same antigen. 7.Many of the daughter cells differentiate to become plasma cells, which produce antibodies. Antibodiesare part of the immune response that eliminates the antigen. C. Antibody-Mediated Immunity ‑effective against extracellular antigens, such as bacteria, viruses (when they are outside cells), and toxins Structure of Antibodies Antibodies-proteins produced in response to an antigen. They are Y-shaped molecules consisting of four polypeptide chains: two identical heavy chains and two identical light chains •variable region-end of each “arm” of the antibody; part that combines with the antigen •constant region-rest of the antibody •gamma globulins-found mostly in the gamma globulin part of plasma •immunoglobulins (Ig)-globulin proteins involved in immunity. The five general classes of antibodies are IgG, IgM, IgA, IgE, andIgD AntibodyTotal Serum AntibodyDescriptionIgG80-85 Activates complement and increases phagocytosis; can cross the placenta and provide immune protection to the fetus and newborn; responsible for Rh reactions, such as hemolytic disease of the newborn IgM5-10 Activates complement and acts as an antigen-binding receptor on the surface of B cells; responsible for transfusion reactions in the ABO blood system; often the first antibody produced in response to an antigen IgA15 Secreted into saliva, into tears, and onto mucous membranes to protect body surfaces; found in colostrum and milk to provide immune protection to the newborn IgE0.002 Binds to mast cells and basophils and stimulates the inflammatory response IgD0,2 Functions as an antigen-binding receptor on B cells Effects of Antibodies •Antibodies directly affect antigens by inactivating the antigens or by binding the antigens together. •Antibodies indirectly affect antigens by activating other mechanisms through the constant region of the antibody.
Chapter 13: Lymphatic System and Immunity @medtech.files | by MAPB 1.Inactivate the antigen 2.Bind antigens together 3.Activate the complement cascade.An antigen binds to an antibody. As a result, the antibody can activate complement proteins, which can produce inflammation, chemotaxis, and lysis. 4.Initiate the release of inflammatory chemicals.An antibody binds to a mast cell or a basophil. When an antigen binds to the antibody, it triggers the release of chemicals that cause inflammation. 5.Facilitate phagocytosis.An antibody binds to an antigen and then to a macrophage, which phagocytizes the antibody and antigen. Antibody Production •primary response-results from the first exposure of a B cell to an antigen; B cell proliferates to form plasma cells and memory cells; plasma cells produce antibodies. •memory B cellsare responsible for the secondary response •secondary response/memory response-occurs when the immune system is exposed to an antigen against which it has already produced a primary response D. Cell-Mediated Immunity ‑a function of cytotoxic T cellsand is most effective against microorganisms that live inside body cells; involved with allergic reactions, control of tumors, and graft rejection Cytotoxic T cells have two main effects: •When activated, cytotoxic T cells form many additional cytotoxic T cells, as well as memory T cells. •The cytotoxic T cells release cytokines that promote the destruction of the antigen or cause the lysis of target cells, such as virally infected cells, tumor cells, or transplanted cells. The memory T cells are responsible for the secondary response. VI. ACQUIRED IMMUNITY •Natural -contact with the antigen or transfer of antibodies occurs as part of everyday living and is not deliberate •Artificial-deliberate introduction of an antigen or antibody into the body has occurred A. Active immunity-immunity is provided by the individual’s own immune system •active natural immunity-antigens are introduced through natural exposure such as disease-causing microorganism •active artificial immunity-antigens are deliberately introduced in a vaccine B. Passive immunity-immunity is transferred from another person or an animal •passive natural immunity-antibodies from the mother are transferred to her child across the placenta or in milk •passive artificial immunity-antibodies produced by another person or an animal are injected antiserum -antibodies that provide passive artificial immunity VII. OVERVIEW OF IMMUNE INTERACTIONS Innate immunity-general response that does not improve with subsequent exposure Adaptive immunity-specific response that improves with subsequent exposure; begins with a macrophage presenting an antigen to a helper T cell •Antibody-mediated immunity-antibodies act against antigens in solution or on the surfaces of extracellular microorganisms •Cell-mediated immunity-cytotoxic T cells act against antigens bound to MHC molecules on the surface of cells; they are effective against intracellular microorganisms, tumors, and transplanted cells. VIII. IMMUNOTHERAPY •Immunotherapy -treats disease by altering immune system function or by directly attacking harmful cells IX. EFFECTS OF AGING ON THE LYMPHATIC SYSTEM AND IMMUNITY •Aging has little effect on the lymphatic system’s ability to remove fluid from tissues, absorb lipids from the digestive tract, or remove defective red blood cells from the blood. •Decreased helper T-cell proliferation results in decreased antibody-mediated and cell-mediated immune responses. •The primary and secondary antibody responses decrease with age. •The ability to resist intracellular pathogens decreases with age.
Chapter 13: Lymphatic System and Immunity @medtech.files | by MAPB X. DISEASES Condition Description Lymphatic System Lymphedema Abnormal accumulation of lymph in tissues, often the limbs; 70%–90% cases in women; can be caused by developmental defects, disease, or damage to the lymphatic system Lymphoma Cancer of lymphocytes that often begins in lymph nodes; immune system becomes depressed, with increased susceptibility to infections Immune SystemImmediate Allergic Reactions •Asthma •AnaphylaxisSymptoms occur within a few minutes of exposure to an antigen because antibodies are already present from prior exposure Antigen combines with antibodies on mast cells or basophils in the lungs, which then release inflammatory chemicals that cause constriction of the air tubes, so that the patient has trouble breathing Systemic allergic reaction, often resulting from insect stings or drugs such as penicillin; chemicals released from mast cells and basophils cause systemic vasodilation, increased vascular permeability, drop in blood pressure, an possibly death Delayed Allergic Reactions Symptoms occur in hours to days following exposure to the antigen because these types of reactions involve migration of T cells to the antigen, followed by release of cytokines Immunodeficiencies •Severe combined immunodeficiency (SCID) •Acquired immunodeficiency syndrome (AIDS)Congenital; both B cells and T cells fail to form; unless patient kept in a sterile environment or provided with a compatible bone marrow transplant, death from infection results Life-threatening disease caused by the human immunodeficiency virus (HIV)
Human Anatomy and Physiology with Pathophysiology CHAPTER 14: RESPIRATORY SYSTEMChapter 14: Respiratory System @medtech.files | by MAPB OUTLINE I.Functions of the Respiratory System II.Anatomy of the Respiratory System A.Nose B.Pharynx C.Larynx D.Trachea E.Bronchi F.Lungs G.Pleural Cavities H.Lymphatic Supply III.Ventilation and Respiratory Volumes IV.Gas Exchange A.Factors That Affect Gas Exchange B.Movement of Gases in the Lungs C.Movement of Gases in the Tissues V.Gas Transport in the Blood VI.Rhythmic Breathing VII.Effects of Aging on the Respiratory SystemVIII.DiseasesI. FUNCTIONS OF THE RESPIRATORY SYSTEM 1.Regulation of blood pH 2.Voice production 3.Olfaction 4.Innate immunity Respiration includes the following processes: 1.ventilation, or breathing, which is the movement of air into and out of the lungs 2.the exchange of O2 and CO2 between the air in the lungs and the blood 3.the transport of O2 and CO2 in the blood 4.the exchange of O2 and CO2 between the blood and the tissues II. ANATOMY OF THE RESPIRATORY SYSTEM Divided into two: •Upper Respiratory Tract oNose oPharynx (throat) oLarynx (voice box) •Lower Respiratory Tract oTrachea (windpipe) oBronchi oLungs A. Nose •Nose-consists of the external nose and the nasal cavity •External nose-visible structure that forms a prominent feature of the face; composed of hyaline cartilage, although the bridge of consists of bone •Nares/nostrils -aka external nares; external openings of the nose •Choanae-aka internal nares; openings into the pharynx •Nasal cavity-extends from the nares to the choanae •Nasal septum-midline wall dividing the nasal cavity into the right and left portions oDeviated nasal septum-occurs when the septum bulges to one side •Hard palate-forms the floor of the nasal cavity separating the oral and nasal cavity •Conchae- nasal concha; 3 prominent bony ridges from the lateral wall of each side of the nasal cavity which increase surface area and cause air to churn for it to be cleansed, humidified, and warmed o3 types:superior, middle, and inferior nasal concha •Paranasal sinuses-air-filled, mucus-lined spaces within the bone that open into the nasal cavity; include the frontal, maxillary, ethmoidal, and sphenoidal sinuses osinusitis-inflammation of the mucous membrane of a sinus •Nasolacrimal duct- carry tears from the eyes, also open into the nasal cavity Sneeze reflex-dislodges foreign substances from the nasal cavity; sensory receptors detect the foreign substances, and action potentials are conducted along the trigeminal nerves to the medulla oblongata, where the reflex is triggered •ACHOO-autosomal-dominant-compelling-helio-ophthalmic-outburst
Chapter 14: Respiratory System @medtech.files | by MAPB B. Pharynx ‑aka throat ‑common passageway for both the respiratory and the digestive systems 3 parts: •Nasopharynx-superior part; lined with pseudostratified ciliated columnar epithelium; where the ff are found: oUvula-grape-like posterior extension of soft palate oSoft palate-floor of the nasopharynx; an incomplete muscle and connective tissue partition separating the nasopharynx from the oropharynx oPharyngeal tonsil- posterior part of the nasopharynx; helps defend the body against infection •Oropharynx-middle position from uvula to epiglottis; where the oral cavity opens into; lined with stratified squamous epithelium, which protects against abrasion oPalatine tonsils-located in the lateral walls near the border of the oral cavity and the oropharynx oLingual tonsil-located on the surface of the posterior part of the tongue •Laryngopharynx-inferior part; from epiglottis to esophagus where food and drinks pass through with air; lined with stratified squamous epithelium and ciliated columnar epithelium C. Larynx ‑aka voice box‑where the vocal cords are found ‑located in the anterior throat and extends from the base of tongue to the trachea Three main functions:•maintains an open airway •protects the airway during swallowing •produces the voice Consists of nine cartilage structures: ‑laryngeal cartilage function as attachment of the vocal cords ‑attached to each other by muscle and ligaments ‑composed of hyaline cartilage except for epiglottis •3 single oThyroid cartilage-aka Adam’s apple; first single and largest cartilage; attached superiorly to the hyoid bone oCricoid cartilage-second single and most inferior; forms the base of the larynx on which the other cartilages rest oEpiglottis-third single and projects superiorly as a free flap toward the tongue; differs from other cartilages in that it consists of elastic cartilage rather than hyaline; closes the airway during swallowing •3 paired oCuneiform cartilage-paired and most superior oCorniculate cartilage-paired and middle oArytenoid cartilage-paired and most inferior; responsible for moving the vocal cords laterally and medially •During normal breathing:vocal cords are open •During speaking:vocal cords come together and vibrate (Arytenoid cartilage moves the vocal cords laterally and medially) •Changing the tension of the vocal folds: olower note–shorten ohigher note–lengthen
Chapter 14: Respiratory System @medtech.files | by MAPB •Vocal folds-true vocal cords •Vestibular folds-false vocal cords •Glottis-opening when vocal folds and vestibular folds are open •Laryngitis -an inflammation of the mucous epithelium of the vocal foldsD. Trachea ‑aka windpipe‑transports air from larynx to the lungs ‑composed of 15-20 C-shaped pieces of hyalin cartilage ‑divides into 2 primary bronchi: left and right primary bronchi cough reflex-smooth muscle of the trachea contracts, decreasing the trachea’s diameter; sensory receptors detect the foreign substance, and action potentials travel along the vagus nerves to the medulla oblongata, where the reflex is triggered E. Bronchi ‑tubes that enter the lungs Divides into: •Left and right main bronchior primary bronchi-supplies each lung; lined with pseudostratified ciliated columnar epithelium oLeft is more horizontal because it is displaced by the heart while the right is more vertical, shorter, and wider; thus, foreign bodies usually lodge in the right •Secondary or lobar bronchi-conduct air to each lung lobe (two in left, three in right) •Tertiary or segmental bronchi-serves a lobule; supply the bronchopulmonary segments •Bronchioles-serves each alveoli •Terminal bronchioles•respiratory bronchioles-subdivides to form the alveolar ducts F. Lungs ‑principal organs of respiration ‑cone-shaped, with its base resting on the diaphragm and its apex extending superiorly to a point about 2.5 cm above the clavicle •Right lung-divided into three lobes by the horizontal and oblique fissures oSuperior lobe oMiddle lobe oInferior lobe •Left lung-divided into two lobes by the oblique fissure oSuperior lobe oInferior lobe •Bronchopulmonary segments-functional division of the lungs o9 in the left o10 in the right •Tracheobronchial tree-consists of the main bronchi and many branches omain bronchi olobar bronchi osegmental bronchi obronchioles oterminal bronchioles orespiratory bronchioles oalveolar ducts-long, branching ducts with many openings into alveoli oalveoli -small air-filled chambers where air and blood come into close contact with each other in capillaries for the purpose of air exchange; lined with simple squamous epithelium oalveolar sacs-chambers connected to two or more alveoli respiratory membrane-where gas exchange between the air and blood takes place; formed mainly by the walls of the alveoli and the surrounding capillaries surfactant-a chemical that reduces the tendency of alveoli to recoil
Chapter 14: Respiratory System @medtech.files | by MAPB G. Pleural Cavities ‑surrounds each lung ‑lined with a serous membrane called the pleuraPleura consists of: •parietal pleura-lines the walls of the thorax, diaphragm, and mediastinum •visceral pleura-covers the surface of the lungs pleural fluid-acts as lubricant; helps hold the pleural membranes together H. Lymphatic Supply •superficial lymphatic vessels-deep to the visceral pleura; drain lymph from the superficial lung tissue and the visceral pleura •deep lymphatic vessels-follow the bronchi; drain lymph from the bronchi and associated connective tissues III. VENTILATION AND RESPIRATORY VOLUMES Ventilation-or breathing; the process of moving air into and out of the lungs. Two phases of ventilation: •inspiration-or inhalation; movement of air into the lungs •expiration-or exhalation; movement of air out of the lungs A. Changing Thoracic Volume •Muscles of inspiration-include the diaphragm and the muscles that elevate the ribs and sternum, such as the external intercostals odiaphragm-large dome of skeletal muscle that separate the thoracic cavity from abdominal cavity •Muscles of expiration-include the internal intercostals and depress the ribs and sternum oQuiet expiration-the external intercostal muscles contract, elevating the ribs and moving the sternum oLabored expiration-additional muscles contract, causing additional expansion of the thorax B. Pressure Changes and Airflow Two physical principles govern the flow of air into and out of the lungs: 1.Changes in volume result in changes in pressure 2.Air flows from an area of higher pressure to an area of lower pressure The volume and pressure changes responsible for one cycle of inspiration and expiration can be described as follows: •Duringinspiration, air flows into the alveoli because atmospheric pressure > alveolar pressure. •During expiration, air flows out of the alveoli because alveolar pressure > atmospheric pressure. End of expiration and inspiration: alveolar pressure = atmospheric pressure •alveolar pressure-air pressure within the alveoli •atmospheric pressure-air pressure outside the body C. Lung Recoil •lung recoil-the tendency for an expanded lung to decrease in size; due to the elastic properties of its tissues and because the alveolar fluid has surface tension •surface tension-exists because the oppositely charged ends of water molecules are attracted to each other Two factors keep the lungs from collapsing: 1.Surfactant-a mixture of lipoprotein molecules produced by secretory cells of the alveolar epithelium; reducing surface tension •Infant respiratory distress syndrome (IRDS)-caused by too little surfactant; aka hyaline membrane disease; common in premature infants 2.Pleural pressure-lower than alveolar pressure because of a suction effect caused by fluid removal by the lymphatic system and by lung recoil D. Changing Alveolar Volume 1.Increasing thoracic volume results in decreased pleural pressure, increased alveolar volume, decreased alveolar pressure, and air movement into the lungs.
Chapter 14: Respiratory System @medtech.files | by MAPB 2.Decreasing thoracic volume results in increased pleural pressure, decreased alveolar volume, increased alveolar pressure, and air movement out of the lungs. E. Respiratory Volumes and Capacities •Spirometry-the process of measuring volumes of air that move into and out of the respiratory system •Spirometer-the device that measures these respiratory volumes •Respiratory volumes-measures of the amount of air movement during different portions of ventilation •Respiratory capacities-sums of two or more respiratory volumes Four measurements of respiratory volume: •Tidal volume-the volume of air inspired or expired with each breath. (about 500 milliliters mL) •Inspiratory reserve volume-the amount of air that can be inspired forcefully beyond the resting tidal volume (about 3000 mL) •Expiratory reserve volume-the amount of air that can be expired forcefully beyond the resting tidal volume (about 1100 mL) •Residual volume-the volume of air still remaining in the respiratory passages and lungs after maximum expiration (about 1200 mL) Sum of two or more pulmonary volumes: •Functional residual capacity-expiratory reserve volume + residual volume; amount of air remaining in the lungs at the end of a normal expiration (about 2300 mL at rest). •Inspiratory capacity-tidal volume + inspiratory reserve volume; amount of air a person can inspire maximally after a normal expiration (about 3500 mL at rest) •Vital capacity-inspiratory reserve volume + tidal volume + expiratory reserve volume; maximum volume of air that a person can expel from the respiratory tract after a maximum inspiration (about 4600 mL) •Total lung capacity-sum of the inspiratory and expiratory reserves and the tidal and residual volumes (about 5800 mL); also equal to the vital capacity plus the residual volume forced expiratory vital capacity-the rate at which lung volume changes during direct measurement of the vital capacity IV. GAS EXCHANGE A. Factors That Affect Gas Exchange •Respiratory Membrane Thickness oincreases during certain respiratory diseases oresult in decreased gas exchange •Surface Area osmall decreases in surface area adversely affect gas exchange during strenuous exercise owhen the surface area is decreased to one-third to one-fourth of normal, gas exchange is inadequate under resting conditions •Partial Pressure-the pressure exerted by a specific gas in a mixture of gases B. Movement of Gases in the Lungs 1.Oxygen diffuses from a higher partial pressure in the alveoli to a lower partial pressure in the pulmonary capillaries. 2.Oxygen diffuses from a higher partial pressure in the tissue capillaries to a lower partial pressure in the tissue spaces. C. Movement of Gases in the Tissues 1.Carbon dioxide diffuses from a higher partial pressure in the tissues to a lower partial pressure in the tissue capillaries. 2.Carbon dioxide diffuses from a higher partial pressure in the pulmonary capillaries to a lower partial pressure in the alveoli. V. GAS TRANSPORT IN THE BLOOD Oxygen Transport •Most (98.5%) O2 is transported bound to hemoglobin. Some (1.5%) O2 is transported dissolved in plasma. •oxyhemoglobin-hemoglobin with O2 bound to its heme groups Carbon Dioxide Transport and Blood pH •Carbon dioxide is transported in solution as plasma (7%), in combination with blood proteins (23%), and as bicarbonate ions (70%). •carbonic anhydrase-an enzyme that is located inside RBC and on the surface of capillary epithelial cells; increases the rate at which CO2 reacts with water to form H+ and HCO3− in the tissue capillaries
Chapter 14: Respiratory System @medtech.files | by MAPB VI. RHYTHMIC BREATHING •The normal rate of breathing in adultsis between 12 and 20 breaths per minute. •In children, the rates are higher and may vary from 20 to 40 per minute. Respiratory Areas in the Brainstem •medullary respiratory center-consists of two dorsal respiratory groups and two ventral respiratory groups odorsal respiratory groups-forming a longitudinal column of cells located bilaterally in the dorsal part of the medulla oblongata; responsible for stimulating contraction of the diaphragm oventral respiratory groups-forming a longitudinal column of cells located bilaterally in the ventral part of the medulla oblongata; responsible for stimulating the external intercostal, internal intercostal, and abdominal muscles ‣pre-Bötzinger complex-known to establish the basic rhythm of breathing •pontine respiratory group-collection of neurons in the pons; play a role in switching between inspiration and expiration Effect of Exercise on Breathing 1.At the onset of exercise, the rate of breathing immediately increases. 2.After the immediate increase in breathing, breathing continues to increase gradually. anaerobic threshold -the highest level of exercise that can be performed without causing a significant change in blood pH VII. EFFECTS OF AGING ON THE RESPIRATORY SYSTEM 1.Vital capacity and maximum minute ventilation decrease because of weakening of the respiratory muscles and stiffening of the thoracic cage. 2.Residual volume and dead space increase because the diameter of respiratory passageways increases. 3.An increase in resting tidal volume compensates for increased dead space, loss of alveolar walls (surface area), and thickening of alveolar walls. 4.The ability to remove mucus from the respiratory passageways decreases. VIII. DISEASES Condition Description Respiratory Disorders Bronchitis Inflammation of bronchi impairs breathing; bronchitis can progress to emphysema Emphysema Destruction of alveolar walls; loss of alveoli decreases surface area for gas exchange; there is no cure; alone or with bronchitis, known as chronic obstructive pulmonary disease(COPD) Adult respiratory distress syndrome (ARDS) Caused by damage to the respiratory membrane; amount of surfactant is reduced lessening gas exchange Cystic fibrosis Genetic disorder that affects mucus secretions throughout the body due to an abnormal transport protein Lung cancer Occurs in the epithelium of the respiratory tract; can easily spread to other parts of the body because of the rich blood and lymphatic supply to the lungs Circulatory SystemThrombosis of the pulmonary arteries Blood clot in lung blood vessels; inadequate blood flow through the pulmonary capillaries, affecting respiratory function Nervous SystemSudden infant death syndrome (SIDS) Most frequent cause of death of infants between 2 weeks and 1 year of age; cause is still unknown, but at-risk babies can be placed on monitors that warn if breathing stops Infectious Diseases of the Respiratory System Upper Respiratory Tract Strep throat Common cold Caused by Streptococcus pyogenes; characterized by inflammation of the pharynx and fever Results from a viral infection Lower Respiratory TractTuberculosisPneumoniaFlu Caused by the bacterium Clostridium tuberculosis, which forms small, lumplike lesions called tubercles Many bacterial or viral infections of the lungs that cause fever, difficulty in breathing, and chest pain Viral infection of the respiratory system; does not affect the digestive system, as is commonly misunderstood
Human Anatomy and Physiology with Pathophysiology CHAPTER 15:DIGESTIVE SYSTEMChapter 15: Digestive System @medtech.files | by MAPB OUTLINE I.Functions of the Digestive System II.Anatomy and Histology of the Digestive System III.Oral Cavity, Pharynx, and Esophagus IV.Stomach V.Small Intestine VI.Liver and Pancreas VII.Large Intestine VIII.Digestion, Absorption, and Transport A.Carbohydrates B.Lipids C.Proteins D.Water and Minerals IX.Effects of Aging on the Digestive System X.DiseasesI. FUNCTIONS OF THE DIGESTIVE SYSTEM 1.Ingestion 2.Digestion 3.Absorption 4.Elimination II. ANATOMY AND HISTOLOGY OF THE DIGESTIVE SYSTEM Digestive tract-aka gastrointestinal tract; series of hollow organs through which food passes Order of food passage: 1.Oral cavity (mouth) 2.Pharynx (throat) 3.Esophagus 4.Stomach 5.Small intestine 6.Large intestine 7.Rectum 8.Anus Accessory organs: •Salivary Glands-secrete amylase •Liver-produces bile •Gallbladder-secretes bile •Pancreas-produce lipase Four Major Tunics/Layers 1.Mucosa-secretes mucus; inner tunic consists of three layers: •mucous epithelium •loose connective tissue (lamina propria) •thin outer layer of smooth muscle (muscularis mucosae) 2.Submucosa-thick layer of loose connective tissue containing nerves, blood vessels, and small glands; plexus 3.Muscularis-consists of: •inner layer of circular smooth muscle•outer layer of longitudinal smooth muscle•sometimes has oblique middle layer (stomach) 4.Serosa (adventitia)-most superficial layer; •adventitia-no peritoneum; composed of connective tissue •serosa -consists of the peritoneum, which is a smooth epithelial layer
Chapter 15: Digestive System @medtech.files | by MAPB Peritoneum •Peritoneum-serous membrane that forms the lining of the abdominal cavity oParietal peritoneum-lines the wall of abdominal cavity oVisceral peritoneum-covers the organs •Mesenteries-connective tissue, holding organs in abdominal cavity oLesser omentum-mesentery connecting the lesser curvature of the stomach to the liver and diaphragm oGreater omentum-mesentery connecting the greater curvature of the stomach to the transverse colon and posterior body wall; abdominal policeman ‣omental bursa -a cavity, or pocket formed by greater omentum •retroperitoneal-behind peritoneum; other abdominal organs that have no mesenteries III. ORAL CAVITY, PHARYNX, AND ESOPHAGUS A. Anatomy of Oral Cavity •Oral cavity -aka mouth; beginning of the one-way digestive tract; stratified squamous epithelia •Lips-muscular structures formed by the orbicularis oris •Cheek-forms the lateral walls and is made of buccinator (flatten the cheeks against the teeth) •Tongue-large, muscular organ that occupies most of the oral cavity •Frenulum-thin fold of tissue anchoring the underside of the tongue to the floor of the mouth 4 types of lingual papillae: •Filiform papillae-conical shape contain fingerlike projections; do not contain taste buds; lined by stratified squamous cornified epithelium •Fungiform papillae-mushroom shape; constricted base and expanded surface; found mostly at the tip of the tongue; contain taste buds; lined by stratified squamous non cornified epithelium •Foliate papillae-leaflike papillae with ridges and rudimentary in man •Circumvallate papillae-large dome shaped; largest of the lingual papillae; contain taste buds Teeth •Permanent teeth or secondary teeth: 32 teeth•Deciduous/ Milk / Primary teeth: 20 teeth•Central incisor-central cutting •Lateral incisor-lateral cutting •Canine-tearing food •First and second premolars-tearing and cutting; each with 2 cusps or points •1st –3rd molars-for grinding; with 3 cusps
Chapter 15: Digestive System @medtech.files | by MAPB Three regions: 1.Crown-superior portion; with one or more cusps 2.Neck-narrow portion 3.Root-largest region of the tooth and anchors it in the jawbone •Pulp-central space between tooth •Dentin-a living, cellular, calcified tissue that surrounds the pulp •Enamel-hard nonliving mineralized substance that covers dentin •Cementum -helps anchor the tooth in the jaw •Gingiva-epithelial covering of alveolar ridges •Periodontal ligaments -secure the teeth in the alveoli by embedding into the cementum •Dental caries-or tooth decay; result of the breakdown of enamel by acids produced by bacteria on the tooth surface •Periodontal disease-inflammation and degeneration of the periodontal ligaments, gingiva, and alveolar bone Palate and Tonsils •Palate-roof of oral cavity oHard palate-anterior part contains bone oSoft palate-posterior portion consists of skeletal muscle and connective tissue ‣uvula-posterior extension of the soft palate •Tonsils-located in the lateral posterior walls of the oral cavity, in the nasopharynx, and in the posterior surface of the tongue Salivary Glands ‑exocrine glands with ducts that empty into the mouth ‑produce saliva contains enzymes to breakdown food •Parotid glands-largest pair, anterior to each ear; flows thru the parotid duct •Submandibular glands-medial to the angle of the mandible which produces mostly serous fluids empties into the floor of the mouth •Sublingual glands-smallest pair and produce primarily mucous secretions Mumps-inflammation of parotid glands B. Saliva ‑a versatile fluid; a mixture of serous (watery) and mucous fluids ‑keep the oral cavity moist and contains enzymes that begin the process of digestion •Salivary amylase-salivary enzyme that breaks down carbohydrates/starch •Lysozyme-salivary enzymes that are active against bacteria •Mucin-a proteoglycan that gives a lubricating quality to the secretions of the salivary glands C. Pharynx ‑aka throat; connects mouth to esophagus ‑3 parts:•Nasopharynx •Oropharynx •Laryngopharynx ‑posterior walls of oropharynx and laryngopharynx are formed by pharyngeal constrictor muscle D. Esophagus ‑long muscular tube connecting the pharynx to the stomach ‑25 cm long; transport food to stomach ‑joins stomach at cardiac opening ‑stratified squamous non keratinized •Upper esophageal sphincter and lower esophageal sphincter-opens and closes to allow passage of food •Submucosa-deep esophageal glands •T.Muscularis: oupper 1/3 skeletal muscle omiddle 1/3 smooth and skeletal muscle olower 1/3 smooth muscle E. Swallowing ‑or deglutition ‑divided into three phases: voluntary, pharyngeal, and esophageal phase
Chapter 15: Digestive System @medtech.files | by MAPB 3 phases: 1.Voluntary Phase- bolus (mass of food) formed in mouth and pushed into oropharynx 2.Pharyngeal Phase- swallowing reflex initiated when bolus stimulates receptors in oropharynx 3.Esophageal Phase- moves food from pharynx to stomach Peristalsis-wave-like contractions moves food through digestive tract IV. STOMACH A. Anatomy of the Stomach Stomach •Enlarged portion of the digestive tract inferior to the diaphragm at the end of the esophagus •Located in abdomen •Storage tank and mixing chamber for food •Can hold up to 2 liters of food •Produces mucus, hydrochloric acid, protein digesting enzymes •Contains a thick mucus layer that lubricates and protects epithelial cells on stomach wall form acidic pH (3) •Lined by simple columnar epithelium •3 muscular layers:outer longitudinal, middle circular, and inner oblique to produce churning action •Cardiac opening-aka lower esophageal sphincter; cardiac region-opening from the esophagus into the stomach region •Body-greater curvature and lesser curvature •Pyloric opening-opening between stomach and small intestine •Pyloric sphincter-thick, ring of smooth muscle around pyloric opening •Rugae-large folds of the mucosa that allow stomach to stretch •Fundus-upper part of stomach •Gastric pits-opening of gastric glands; tubelike found in mucosal surface 5 Groups of Epithelial Cells •Surface Mucous Cells -goblet cells which secrete alkaline mucus to protect itself from acid •Mucous neck cells-goblet cells that secretes acidic fluid •Parietal cells-very pale cells which produce HCl and intrinsic factor (for digestion of vitamin B12) •Chief cells-darker staining cells which produce pepsinogen, a precursor hormone for pepsin –w/c digests proteins •Endocrine cells-produce regulatory chemicals •G cells-secrete gastrin which triggers HCl production in parietal cells B. Secretions of the Stomach Chyme-paste-like substance that forms when food begins to be broken down; semifluid mixture; food + stomach secretions •HCl-produces a pH of about 2.0; kills microorganism •Pepsin-active form of pepsinogen; breaks down protein •Mucus-forms a thick layer; lubricates the the epithelial cells •Intrinsicfactor-binds to Vitamin B12 Heartburn-or gastritis; painful or burning sensation in the chest; occurs when gastric juices regurgitate into esophagus; caused by caffeine, smoking, or eating or drinking in excess FluidSourceFunctionMouthSaliva (water, bicarbonate ions, mucus) Salivary glands Moistens and lubricates food, neutralizes bacterial acids, flushes bacteria from oral cavity Salivary amylase Salivary glands Digests starch
Chapter 15: Digestive System @medtech.files | by MAPB Lysozyme Salivary glands Has weak antibacterial action StomachHydrochloric acid Gastric glands Kills bacteria, converts pepsinogen to pepsin Pepsin* Gastric glands Digests protein Mucus Mucous cells Protects stomach lining Intrinsic factor Gastric glands Binds to vitamin B12, aids in its absorption Small Intestine and Associated GlandsBile salts Liver Emulsify fats Bicarbonate ions Pancreas Neutralize stomach acid Trypsin*, chymotrypsin*, carboxy-peptidase* Pancreas Digest protein Pancreatic amylase Pancreas Digests starch Lipase Pancreas Digests lipid (triglycerides) Nucleases Pancreas Digest nucleic acid (DNA or RNA) Mucus Duodenal glands and goblet cells Protects duodenum from stomach acid and digestive enzymes Peptidases** Small intestine Digest polypeptide Sucrase** Small intestine Digests sucrose Lactase** Small intestine Digests lactose Maltase** Small intestine Digests maltose *These enzymes are secreted as inactive forms, then activated. **These enzymes remain in the microvilli. C. Regulation of Stomach Secretions 1.Cephalic phase-1st phase; stomach secretions are initiated by sight, smell, taste, or food thought •Parasympathetic stimulation •gastrin, histamine increase stomach secretions •Gastrin- hormone that enters the blood and is carried back to the stomach; stimulates additional secretory activity •Histamine-stimulate gastric gland secretion; stimulates HCl acid production 2.Gastric phase-2nd phase; partially digested proteins and distention of stomach promote secretion 3.Intestinal phase-3rd phase; acidic chyme stimulates neuronal reflexes and secretions of hormones that inhibit gastric secretions by negative feedback loops Secretin-released from the duodenum in response to low pH Cholecystokinin-stimulated when fatty acids and peptides are released; inhibits gastric secretion Major Digestive System Hormones HormoneSourceFunctionGastrinGastric glands -Increases gastric secretions SecretinDuodenum -Decreases gastric secretions -Increases pancreatic and bile secretions high in bicarbonate ions -Decreases gastric motility Cholecysto-kininDuodenum -Decreases gastric secretions -Strongly decreases gastric motility -Increases gallbladder contraction -Increases pancreatic enzyme secretion D. Movement in Stomach •Mixing waves-weak contraction; thoroughly mix food to form chyme •Peristaltic waves-stronger contraction; force chyme toward and through pyloric sphincter •Hormonal and neural mechanisms stimulate stomach secretions •Stomach empties every 4 hours after regular meal, and 6-8 hours after high fatty meal •Distention of the stomach wall-major stimulus to gastric motility & emptying •Cholecystokinin-major inhibitor of motility and emptying •Hunger pangs-stomach is stimulated to contract by low blood glucose levels usually 12-24 hours after a meal V. SMALL INTESTINE A. Anatomy of the Small Intestine •Long narrow tubes that folds to fill a large portion of the abdominal cavity •Measures 6 meters in length •Major absorptive organ •Chyme takes 3-5 hours to pass through •Contains enzymes to further breakdown food •Contains secretions for protection against chyme’s acidity•Simple Columnar epithelium
Chapter 15: Digestive System @medtech.files | by MAPB Parts of Small Intestine •Duodenum‑C-shaped beginning of SI; shortest and receives partial digestive food; for chemical digestion of food ‑25 cm long ‑contains absorptive cells, goblet cells, granular cells, endocrine cells ‑contains microvilli and many folds ‑contains bile and pancreatic ducts •Jejunum‑middle and longest section; absorption of important nutrients such as sugars, fatty acids, and amino acids ‑2.5 meters long •Ileum‑main function is to absorb vitamin B12, bile salts, and other analytes not absorbed by the jejunum; the wall is made up of folds with many tiny finger-like projections known as villi on its surface ‑meters long Three Modifications That Increase Surface Area •circular folds-run perpendicular to the long axis of the digestive tract •villi-tiny, fingerlike projections of the mucosa •microvilli- numerous cytoplasmic extensions lacteal-a lymphatic capillary; important in transporting absorbed nutrients 4 Major Cell Types in the Mucosa •Absorptive cells-contain microvilli; produce digestive enzymes, and absorb digested food •Goblet cells-produces a protective mucus •Granular cells-protect the intestinal epithelium from bacteria •Endocrine cells-produce regulatory hormone intestinal glands-or crypts of Lieberkühn; tubular glands of the mucosa duodenal glands-open into the base of the intestinal glands Ileocecal junction-site where the ileum connects to the large intestine; consist of: •ileocecal sphincter-a ring of smooth muscle •ileocecal valve-allow the intestinal contents to move from the ileum to the large intestine Peyerpatches-clusters of lymphatic nodules in the ileum; protection from microorganisms B. Secretions of the Small Intestine •Peptidases-digest proteins; they break the peptide bonds in proteins to form amino acids •Disaccharidases-digest small sugars, specifically disaccharides C. Movement in the Small Intestine •Peristaltic contractions-cause the chyme to move along the small intestine •Segmental contraction-propagated only for short distance; mix intestinal content D. Absorption in the Small Intestine •Most absorption: duodenum andjejunum VI. LIVER AND PANCREAS A. Anatomy of the Liver •Processes nutrients and detoxifies harmful substances from the blood •Large gland in the RUQ that produces bile that is stored in the gallbladder and secreted into the duodenum •Weighs about 3 lbs. •Consist of two lobes: right and left lobe •falciform ligament-connective tissue septum that separates the right and left lobes •porta-gate where blood vessels, ducts, nerves enter and exit •lobules-divisions of liver with portal triads at corners
Chapter 15: Digestive System @medtech.files | by MAPB •Portal triad-contain hepatic artery, hepatic portal vein, hepatic duct •Hepatic artery-delivers oxygenated blood to the liver, which supplies liver cells with oxygen •Hepatic portal vein-carries nutrient-rich blood from the digestive tract to the liver •Hepatic veins-where blood exits the liver; empty into the inferior vena cava •Hepatic cords-between center margins of each lobule; separated by hepatic sinusoids; formed by hepatocytes (liver cells) •Hepatic sinusoids- blood channels that separates hepatic cords; contain phagocytic cells that remove foreign particles from blood •Central vein-center of each lobule; where mixed blood flows towards; forms hepatic veins •Bile canaliculus-a cleft like lumen between the cells of each hepatic cord Gallbladder ‑small sac on inferior surface of liver ‑stores and concentrates bile (30-50ml) Liver Ducts •Hepatic duct-collects bile from the liver and fuse to become the common hepatic duct •Common hepatic duct-joins the cystic duct from the gallbladder to become the common bile duct •Cystic duct-joins common hepatic duct; from gallbladder •Common bile duct-carries bile from the gallbladder or liver and brings it to the duodenum B. Functions of the Liver •Digestive and excretory functions •Stores and processes nutrients •Detoxifies harmful chemicals •Synthesizes new molecules •Secretes 700ml of bile each day oBile-important for digestion because it neutralizes acid and dramatically increases fat digestion and absorption oBile salts-emulsify fats, breaking the fat globules into smaller droplets oBilirubin-a bile pigment that results from the breakdown of hemoglobin oGallstones-may form if the amount of cholesterol secreted by the liver becomes excessive C. Anatomy of the Pancreas •Endo and exocrine gland cradled in the duodenum •Produces pancreatic juices which flow through the pancreatic duct •Located retroperitoneal •Head near midline of body •Tail extends to left and touches spleen •Endocrine tissues have pancreatic isletor islets of Langerhansthat produce insulin and glucagon •Exocrine tissues produce digestive enzymes •Acini-produce digestive enzymes •Pancreatic duct-joins the common bile duct and empties into the duodenum •Hepatopancreatic ampulla-bulb-like structure which opens into the duodenum to aid in digestion D. Functions of the Pancreas Exocrine Secretions of Pancreas: •Bicarbonate ion (HCO3-)-neutralizes chyme •Trypsin & Chymotrypsin-split whole and partially digested proteinsinto peptides•Carboxypeptidase-splits peptides into individual amino acids •Pancreatic amylase-continues the polysaccharide digestion •Lipase-lipid digesting enzyme •Nucleases-enzymes that degrade DNA, RNA to nucleotides
Chapter 15: Digestive System @medtech.files | by MAPB VII. LARGE INTESTINE A. Anatomy of the Large Intestine •Cecum-joins small intestine at ileocecal junction; absorbs water and salt residues; on its posterior wall attach is your appendix(wormlike blind sac; 9 cm structure that is often removed) •Colon-1.5 meters long; reabsorbs fluid and process waste products with 4 parts: ascending, transverse, descending, and sigmoid 1.Ascending colon-extends superiorly from the cecum to the right colic flexure, near the liver, where it turns to the left 2.Transverse colon-extends from the right colic flexure to the left colic flexure near the spleen, where the colon turns inferiorly 3.Descending colon-extends from the left colic flexure to the pelvis, where it becomes the sigmoid colon 4.Sigmoid colon-forms an S-shaped tube that extends medially and then inferiorly into the pelvic cavity and ends at the rectum ocrypts-straight, tubular glands in the muscular lining of the colon oteniae coli-three bands in the intestinal wall •Rectum-straight tube that begins at sigmoid and ends at anal canal •Anal canal-canal that exits to the outside; last 2-3 cm of dig. tract oInternal anal sphincter-smooth muscle oExterna anal sphincter-skeletal muscle oHemorrhoids-enlarged or inflamed rectal, or hemorrhoidal, veins that supply the anal canal B. Functions of the Large Intestine •Food takes 18-24 hours to pass through the large intestine and 3-5 hours for chyme to move through small intestine •Feces is product of water, indigestible food, and microbes •Microbes synthesize vitamin K Defecation reflex •Stimulus: fecal distention of rectal wall •Mediated by parasympathetic reflexes •Effect: peristaltic contractions in the lower colon and rectum VIII. DIGESTION, ABSORPTION, AND TRANSPORT 1.Digestion-breakdown of food to molecules •Mechanical Digestion- breaks large food particles into smaller ones •Chemical Digestion-breaking of covalent bonds into organic molecules by digestive enzymes 2.Propulsion-moves food through digestive tract includes swallowing and peristalsis 3.Absorption-primarily in duodenum and jejunum of small intestine 4.Defecation-elimination of waste in the form of feces A. Carbohydrates Carbohydratesconsist primarily of starches, cellulose, sucrose (table sugar), and small amounts of fructose (fruit sugar) and lactose (milk sugar). •Polysaccharides split into disaccharides by salivary and pancreatic amylases •Disaccharides broken down into monosaccharides by disaccharidaseson surface of intestinal epithelium •Glucose is absorbed by cotransport with Na+ into intestinal epithelium •Glucose is carried by hepatic portal vein to liver and enters most cells by facilitated diffusion B. Lipids •Lipidmolecules are insoluble or only slightly soluble in water •Triglycerides-or fats, are the most common type of lipid oSaturated fats-fatty acids have only single bonds between carbons oUnsaturated fats-fatty acids have double bonds between carbons •Emulsification -bile salts transform large lipid dropletsinto much smaller lipid droplets•Bile saltsemulsify lipids •Lipasebreaks down lipids which form micelles•Micellesare in contact with intestinal epi. and diffuse with cells where they are packaged and released into lacteals •Lipids are stored in adipose tissue and liver
Chapter 15: Digestive System @medtech.files | by MAPB C. Proteins •Proteins are split into polypeptides by enzymes secreted by stomach and pancreas •Peptides and amino acids are absorbed into intestinal epi. cells •Amino acids are actively transported into cells (help from GH and insulin) •Amino acids used to build new proteins D. Water and Minerals •Water can move across intestinal wall in either direction •Depends on osmotic conditions •99% of water entering intestine is absorbed •Minerals are actively transported across wall of small intestine IX. EFFECTS OF AGING ON THE DIGESTIVE SYSTEM •With advancing age, the layers of the digestive tract thin, and the blood supply decreases. •Mucus secretion and motility also decrease in the digestive tract. •The defenses of the digestive tract decline, leaving it more sensitive to infection and the effects of toxic agents. •Tooth enamel becomes thinner, and the gingiva recede, exposing dentin, which may become painful and affect eating habits. X. DISEASES Condition Description Stomach Peptic ulcer lesions in the lining of the stomach or duodenum, usually due to infection by the bacterium Helicobacter pyloriLiver Cirrhosis characterized by damage to and death of hepatic cells and replacement by connective tissue Hepatitis inflammation of the liver that causes liver cell death and replacement by scar tissue Hepatitis A infectious hepatitis; usually transmitted by poor sanitation practices or from mollusks living in contaminated waters Hepatitis B serum hepatitis; usually transmitted through blood or other body fluids through either sexual contact or contaminated hypodermic needles Hepatitis C often a chronic disease leading to cirrhosis and possibly cancer of the liver Intestine Inflammatory bowel disease (IBD) localized inflammatory degeneration that may occur anywhere along the digestive tract but most commonly involves the distal ileum and proximal colon Irritable bowel syndrome (IBS) disorder of unknown cause marked by alternating bouts of constipation and diarrhea Gluten enteropathy (celiac disease) malabsorption in the small intestine due to the effects of gluten, a protein in certain grains, especially wheat Constipation slow movement of feces through the large intestine, causing the feces to become dry and hard because of increased fluid absorption while being retained Infections of the Digestive Tract Food poisoning caused by ingesting bacteria or toxins, such as Staphylococcus aureus, Salmonella, or Escherichia coliGiardiasis caused by a protozoan, Giardia lamblia, that invades the intestine Intestinal parasites common under conditions of poor sanitation; parasites include tapeworms, pinworms, hookworms, and roundworms Dysentery severe form of diarrhea with blood or mucus in the feces; can be caused by bacteria, protozoa, or amoebae
Human Anatomy and Physiology with Pathophysiology CHAPTER 16: URINARY SYSTEM AND FLUID BALANCEChapter 16:Urinary System and Fluid Balance @medtech.files | by MAPB OUTLINE I.Functions of the Urinary System II.Anatomy of the Kidneys A.Location and External Anatomy of the Kidneys B.Internal Anatomy and Histology of the Kidneys C.Arteries and Veins III.Urine Production A.Filtration B.Tubular Reabsorption C.Tubular Secretion IV.Regulation of Urine Concentration and Volume V.Urine Movement A.Anatomy and Histology of the Ureters, Urinary Bladder, and Urethra B.Micturition Reflex VI.Body Fluid Compartments VII.Regulation of Extracellular Fluid Composition VIII.Regulation of Acid-Base Balance IX.DiseasesI. FUNCTIONS OF THE URINARY SYSTEM 1.Excretion 2.Regulation of blood volume and pressure 3.Regulation of the concentration of solutes in the blood. 4.Regulation of extracellular fluid pH 5.Regulation of red blood cell synthesis 6.Regulation of vitamin D synthesis Components: •2 Kidneys •2 Ureters •1 Urinary bladder •1 Urethra II. ANATOMY OF THE KIDNEYS A. Location and External Anatomy of the Kidneys Kidney ‑bean-shaped organs ‑behind the peritoneum (retroperitoneal), with one kidney on each side of the vertebral column ‑main function is to eliminate waste product through urination ‑weighs 5 oz. (bar of soap or size of fist) ‑between 12th thoracic and 3rd lumbar vertebra ‑right kidney lower than the left •Renal Fat Pad-adipose tissue that surrounds and protects each kidney •Renal Capsule-layer of connective tissue that surrounds each kidney; protects and acts as a barrier •Hilum-indentation on medial side of kidney where blood vessels and nerves exit •Renal Sinus-fat-filled cavity containing the blood vessels, adipose tissue, and collecting tubes B. Internal Anatomy and Histology of the Kidneys •Renal cortex-outer region •Renal medulla-inner region •Renal pyramids-cone-shaped section of the medulla; junction between cortex and medulla •Renal papilla-tip of the pyramids where urine is collected before it is brought to the renal calyx •Renal calyx-funnel-shaped structure which when joined together forms the renal pelvis
Chapter 16: Urinary System and Fluid Balance @medtech.files | by MAPB •Renal pelvis- where calyces join; wide section of the urinary channel where the smaller tubules exit before going to the ureter •Ureter -exits the kidney and connects to the urinary bladder Nephron ‑functional unit of the kidney; composed of a renal corpuscle and a renal tubule Two types of nephrons: •juxtamedullary nephrons-15% of the nephron; have loops of Henle that extend deep into the medulla of the kidney •cortical nephrons-remining 85%; have loops of Henle that do not extend deep into the medulla Components of Nephron •Renal Corpuscle-roughly spherical structure at the beginning of the nephron oGlomerulus-ball of glomerular capillaries oBowman’s Capsule- enlarged end of nephron; double walled capsule surrounding the Glomerulus with specialized cells called Podocytes•Proximal Convoluted Tubule-narrow coiled channel from the Bowman’s capsule•Loop of Henle-has 2 parts: Descending loop (medulla) and returns as the Ascending loop (cortex); water and solutes pass through thin walls by diffusion •Distal Convoluted Tubule-receives the filtrate from the loop; between Loop of Henle and collecting duct •Collecting duct-empties into calyces; carry fluid from cortex through medulla •Papillary duct -where collecting duct drains and empty their contents into calyx•Filtration membrane -in renal corpuscle oendothelium of glomerular capillaries opodocytes obasement membrane•Filtrate-fluid that passes across filtration membrane •Afferent arteriole-supplies blood to the glomerulus for filtration •Efferent arteriole-transports the filtered blood away from the glomerulus •Juxtaglomerular apparatus-located next to the glomerulus; consists of a unique set of afferent arteriole cells and specialized cells in the distal convoluted cells that are in close contact with each other oJuxtaglomerular cells -specialized smooth muscle cells found at the point where the afferent arteriole enters the renal corpuscle oMacula densa-group of specialized cells in distal convoluted tubule Flow of Filtrate Through Nephron 1.Renal corpuscle 2.Proximal tubule 3.Descending loop of Henle 4.Ascending loop of Henle 5.Distal tubule 6.Collecting duct 7.Calyx 8.Renal pelvis 9.Ureter C. Arteries and Veins Blood Flow through Kidneys 1.Renal artery-branch off the abdominal aorta and enter the kidneys 2.Interlobar artery-pass between the renal pyramids 3.Arcuate artery-between the cortex and the medulla 4.Interlobular artery-project into the cortex 5.Afferent arteriole 6.Glomerulus 7.Efferent arteriole 8.Peritubular capillaries-surround the proximal convoluted tubules, the distal convoluted tubules, and the loops of Henle
Chapter 16: Urinary System and Fluid Balance @medtech.files | by MAPB 9.Vasa recta-specialized portions of the peritubular capillaries that extend deep into the medulla and surround loops of Henle and collecting ducts 10.Interlobular vein 11.Arcuate vein 12.Interlobar vein 13.Renal veinIII. URINE PRODUCTION 1.Glomerular Filtration 2.Tubular Reabsorption 3.Tubular Secretion A. Filtration -a nonspecific process whereby materials are separated based on size or charge •Movement of water, ions, small molecules through filtration membrane into Bowman’s capsule to form filtrate •19% of plasma becomes filtrate •180 Liters of filtrate are produced by the nephrons each day •1% of filtrate (1.8 L) become urine rest is reabsorbed •Only small molecules are able to pass through filtration membrane •Formation of filtrate depends on filtration pressure •Filtration pressure-forces fluid across filtration membrane; is influenced by blood pressure •glomerular capillary pressure -blood pressure in the glomerular capillary•capsular pressure-due to the pressure of filtrate already inside the Bowman capsule •colloid osmotic pressure-pressure inside the glomerular capillary B. Tubular Reabsorption •99% of filtrate is reabsorbed and reenters circulation •proximal tubule is primary site for reabsorption of solutes and water •descending Loop of Henle concentrates filtrate •reabsorption of water and solutes from distal tubule and collecting duct is controlled by hormones C. Tubular Secretion •water, small ions, by products of metabolism, drugs, urea are found in urine •solutes are secreted across the wall of the nephron into the filtrate IV. REGULATION OF URINE CONCENTRATION AND VOLUME Hormonal Mechanisms A. Renin-Angiotensin-Aldosterone Mechanism ‑initiated under low blood pressure conditions 1.Reninis produced by the kidneys and converts angiotensinogen, which is produced in the liver, to the hormone angiotensin I2.Angiotensin-converting enzymeconverts angiotensin I to angiotensin II 3.Angiotensin IIcauses vasoconstriction 4.Angiotensin IIacts on adrenal cortex to release aldosterone 5.Aldosteroneincreases rate of active transport of Na+ in distal tubules and collecting duct 6.Volume of water in urine decreases B. Antidiuretic Hormone Mechanism ‑stimulated by a high blood solute concentration ‑ADHincreases the permeability of the distal convoluted tubules and collecting ducts to water 1.ADHis secreted by posterior pituitary gland 2.ADH acts of kidneys and they absorb more water (decrease urine volume) 3.Result is maintain blood volume and blood pressure
Chapter 16: Urinary System and Fluid Balance @medtech.files | by MAPB C. Atrial Natriuretic Hormone ‑triggers by increased blood pressure 1.ANHis secreted from cardiac muscle to right atrium of heart when blood pressure increases 2.ANH acts on kidneys to decrease Na+ reabsorption 3.Sodium ions remain in nephron to become urine 4.Increased loss of sodium and water reduced blood volume and blood pressure V. URINE MOVEMENT A. Anatomy and Histology of the Ureters, Urinary bladder, and Urethra •Ureters- small tubes that carry urine from renal pelvis of kidney to bladder •Urinary Bladder- hollow, muscular container that lies in the pelvic cavity just posterior to the pubic symphysis; stores urine; can hold a few ml to a max. of 1000 ml •Urethra- tube that exits bladder; carries urine from urinary bladder to outside of body otrigone-triangle-shaped portion of the urinary bladder located between the opening of the ureters and the opening of the urethra ointernal urethral sphincter-prevents urine leakage from the urinary bladder oexternal urethral sphincter-allows a person to voluntarily start or stop the flow of urine through the urethra B. Micturition reflex -activated by stretch of urinary bladder wall •Action potentials are conducted from bladder to spinal cord through pelvic nerves •Parasympathetic action potentials cause bladder to contract •Stretching of bladder stimulates sensory neurons to inform brain person needs to urinate V. BODY FLUID COMPARTMENTS 1.Intracellular fluid-includes the fluid inside all the cells of the body; two-thirds of all the water in the body is in the 2.intracellular fluid compartment 3.Extracellular fluid-includes all the fluid outside the cells; includes the interstitial fluid, plasma within blood vessels, and fluid in the lymphatic vessels VII. REGULATION OF EXTRACELLULAR FLUID COMPOSITION A. Thirst Regulation •Water intake is controlled by neurons in the hypothalamus, collectively called the thirst center •Concentration of blood increase thirst center responds by initiating sensation of thirst •When water is consumed, conc. of blood decreases and sensation of thirst decreases Ion Concentration Regulation •Sodium ionsare the dominant extracellular ions. •Aldosteroneincreases Na+ reabsorption from the filtrate •ADHincreases water reabsorption from the nephron •ANHincreases Na+ loss in the urine. •PTH-increases extracellular Ca2+ levels by •Calcitonin-lowers blood Ca2+ levels when they are too high VIII. REGULATION OF ACID-BASE BALANCE A. Buffers ‑chemicals resist change in pH of a solution ‑buffers in body contain salts of weak acids or bases that combine with H+ 3 classes of buffers: •proteins •phosphate buffer •bicarbonate buffer B. Respiratory System •responds rapidly to change in pH •increased respiratory rate raise pH due to rate of carbon dioxide elimination being increased •reduced respiratory rate reduced pH due to rate of carbon dioxide elimination being reduced
Chapter 16: Urinary System and Fluid Balance @medtech.files | by MAPB C. Kidneys •Nephrons secrete H+ into urine and directly regulate pH of body fluids •More H+ if pH is decreasing and less H+ if pH is increasing D. Acidosis and Alkalosis •Acidosis-occurs when pH of blood falls below 7.35 orespiratory acidosis-results when the respiratory system is unable to eliminate adequate amounts of CO2 ometabolic acidosis-results from excess production of acidic substances •Alkalosis-occurs when pH of blood increases above 7.45 orespiratory alkalosis-results from hyperventilation, as can occur in response to stress ometabolic alkalosis-usually results from the rapid elimination of H+ from the body IX. DISEASES Condition Description Inflammation of the Kidneys Glomerulonephritis inflammation of the filtration membrane within the renal corpuscle, causing increased membrane permeability Acute glomerulonephritis often occurs 1–3 weeks after a severe bacterial infection, such as strep throat; normally subsides after several days Chronic glomerulonephritis long-term and progressive process whereby the filtration membrane thickens and is eventually replaced by connective tissue and the kidneys become nonfunctional Renal Failure -can result from any condition that interferes with kidney function Acute renal failure occurs when damage to the kidney is rapid and extensive; leads to accumulation of wastes in the blood Chronic renal failure results from permanent damage to so many nephrons that the remaining nephrons are inadequate for normal kidney function
Human Anatomy and Physiology with Pathophysiology CHAPTER 17: REPRODUCTIVE SYSTEMChapter 17: Reproductive System @medtech.files | by MAPB OUTLINE I.Functions of the Reproductive System II.Formation of Gametes III.Male Reproductive System A.Scrotum B.Testes C.Spermatogenesis D.Ducts E.Penis F.Glands G.Secretions IV.Physiology of Male Reproduction V.Female Reproductive System A.Ovaries B.Oogenesis and Fertilization C.Uterine Tubes D.Uterus E.Vagina F.External Genitalia G.Mammary Glands VI.Physiology of Female Reproduction VII.Effects of Aging on the Reproductive SystemVIII.Diseases I. FUNCTIONS OF THE REPRODUCTIVE SYSTEM 1.Production of gametes 2.Fertilization 3.Development and nourishment of a new individual 4.Production of reproductive hormones II. FORMATION OF GAMETES •Gametes -spermin males and oocytes(eggs) in females•Meiosis-special type of cell division that leads to formation of sex cells; produce four daughter cells •Each sperm cell and each oocyte contain 23 chromosomes Two divisions Meiosis I (reduction division)1.Early prophase I-the duplicated chromosomes become visible chromatids 2.Middle prophase I-pairs of chromosomes synapse. Crossing over may occur at this stage. 3.Metaphase I-pairs of chromosomes align along the center of the cell. Random assortment of chromosomes occurs. 4.Anaphase I-chromosomes move apart to opposite sides of the cell 5.Telophase I-new nuclei form, and the cell divides. Each cell now has two sets of half the chromosomes Meiosis II 6.Prophase II-each chromosome consists of two chromatids 7.Metaphase II-chromosomes align along the center of the cell 8.Anaphase II-chromatids separate, and each is now called a chromosome 9.Telophase II -new nuclei formaround thechromosomes.The cells divide toform four daughtercells with half asmany chromosomesas the parent cell•synapsis-a process where chromosomes align as pairs •crossing over-allows the exchange of genetic material between chromosomes •fertilization-union of sperm and oocyte •zygote-what develops after fertilization; develops into an embryo 3-14 days after fertilization •embryo-14-56 days after fertilization •fetus-56 days after fertilization III. MALE REPRODUCTIVE SYSTEM Consists of: •Testes •Series of ducts oEpididymis oDuctus deferens/ vas deferens oUrethra •Accessory glands oSeminal vesicles oProstate gland oBulbourethral glands •Supporting structures oScrotum oPenis
Chapter 17: Reproductive System @medtech.files | by MAPB Functions •Produce sperm cells (sex cells) •Produce male sex hormones •Transfer sperm cells to female A. Scrotum ‑a saclike structure containing the testes ‑contains dartos muscle(layer of loose connective tissue and a layer of smooth muscle) that moves scrotum and testes close to and away from body depending on temp ‑sperm must develop at temperature less than body temperature ‑cremaster muscles-extensions of abdominal muscles that enter the scrotum B. Testes ‑or male gonads‑primary sex organ ‑produces sperm ‑oval organs, each about 4–5 cm long, within the scrotum •Capsule- thick, white connective tissue that divides the testes into lobes•Seminiferous Tubules -long coiled tubes; site of sperm cell development •interstitial cellsorLeydig cells -secrete testosterone •germ cells-begin of sperm cell •sustentacular cellsor Sertoli cells-nourish germ cells and produce hormones C. Spermatogenesis ‑formation of sperm cells ‑begins at puberty •interstitial cells increase in number and size •seminiferous tubules enlarge •seminiferous tubules produce germ cells and Sustentacular cells Production of Sperm Cells 1.Germ cells-partially embedded in the sustentacular cells 2.Spermatogonia- cells from which sperm cells arise; divide through mitosis; one daughter cell remains a spermatogonium3.Primary spermatocytes 4.Secondary spermatocytes 5.Spermatids-form mature sperm cells 6.Sperm cellsor spermatozoonSperm Cells Structure •Head-contain a nucleus and DNA •Midpiece-contain mitochondria •Tail-flagellum for movement acrosome-a vesicle which contains enzymes that are released during the process of fertilization; necessary for the sperm cell to penetrate the oocyte Path of Sperm 1.Seminiferous tubules 2.Rete Testis 3.Efferent ductules 4.Epididymis
Chapter 17: Reproductive System @medtech.files | by MAPB 5.Ductus (vas) deferens 6.Ampulla 7.Ejaculatory duct 8.Urethra where semen exit body Some Real Energetic Earthworms Divide And Even Unite D. Ducts Epididymis ‑a tightly coiled series of threadlike tubules that form a comma-shaped structure on the posterior side of the testis ‑where seminiferous tubules empty new sperm ‑where sperm continue to mature develop ability to swim and bind to oocytes •rete Testis-network of tubes that empties into the efferent ductules •efferent ductules-carry sperm cells from the testis to epididymis •capacitation-final changes in sperm cells; occur after ejaculation of semen into the vagina and prior to fertilization Ductus Deferens ‑or vas deferens‑extends from epididymis and joins seminal vesicle ‑cut during a vasectomy Spermatic cord: •ductus deferens •testicular artery and veins •lymphatic vessels, •testicular nerve Seminal Vesicle and Ejaculatory Duct •seminal vesicle-a sac-shaped gland near the ampulla of each ductus deferens •ejaculatory duct-union of vas deferens and seminal vesicles; carries semen to the urethra Urethra‑extends from urinary bladder to end of penis ‑passageway for urine and male reproductive fluids (not at same time) Three parts: •prostatic urethra-passes through the prostate gland •membranous urethra-passes through the floor of the pelvis and is surrounded by the external urinary sphincter •spongy urethra-extends the length of the penis and opens at its end E. Penis ‑male organ of copulation and functions in the transfer of sperm cells to female; excrete urine Three columns of erectile tissue: •corpora cavernosa-two columns of erectile tissue that form the dorsal portion and the sides of the penis •corpus spongiosum-third, smaller erectile column occupies the ventral portion of the penis •spongy urethra- passes through the corpus spongiosum and opens to the exterior as the external urethral orificeerection - engorgement of the erectile tissue with blood which causes the penis to enlarge and become firm glans penis-head of the penis; covered with prepuceor foreskinF. Glands Two seminal vesicles:•Prostate gland-surrounds the urethra and the two ejaculatory ducts; consists of both glandular and muscular tissue; size and shape of a walnut
Chapter 17: Reproductive System @medtech.files | by MAPB •Bulbourethral gland-or Cowper glands; pair of small, mucus-secreting glands located near the base of the penis G. Secretions Semen ‑mixture of sperm cells and secretions from male reproductive glands ‑provides a transport medium and nutrients that protect and activate sperm •60% of fluid is from seminal vesicles •30% of fluid is from prostate gland •5% of fluid is from bulbourethral gland •5% of fluid is from testes Mucous secretions from the bulbourethral glandsfunctions: •lubrication of the urethra •neutralization of the contents of the normally acidic urethra •providing a small amount of lubrication during intercourse •reduction of acidity in the vagina Mucus-like secretion of the seminal vesiclescontains substances:•Fructose-nourish the sperm cells as they move through the female reproductive tract •Coagulation proteins-help thicken the semen, which keeps the sperm cells in the vagina for a longer period of time •Enzymes-help destroy abnormal sperm cells •Prostaglandins-stimulate smooth muscle contractions of the female reproductive tract to propel sperm cells through the tract Function of secretions of the prostate1.Regulate pH 2.Liquefy the coagulated semen Testicular secretions-include sperm and small amount of fluid. •2-5 ml of semen is ejaculated each time •1 ml of semen contains 100 million sperm •sperm can live for 72 hours once inside female IV. PHYSIOLOGY OF MALE REPRODUCTION Hormones control: •the development of reproductive structures •the development of secondary sexual characteristics •spermatogenesis •some aspects of sexual behavior Mature neural mechanisms are primarily involved in: •controlling the sexual act •expression of sexual behavior A. Regulation of Reproductive Hormone Secretion Hormone Source Target Tissue Response Gonadotropin-releasinghormone (GnRH)Hypothalamus Anterior pituitary Stimulates secretion of LH and FSH Luteinizing hormone (LH)Anterior pituitary Interstitial cells of the testes Stimulates synthesis and secretion of testosterone Follicle-stimulating hormone (FSH)Anterior pituitary Seminiferous tubules (sustentacular cells) Supports spermatogenesis and inhibin secretion TestosteroneInterstitial cells of testes Testes; body tissues Anterior pituitary and hypothalamus Development of reproductive organs and secondary sexual characteristics; supports spermatogenesis Inhibits GnRH, LH, and FSH secretion through negative feedback InhibinSustentacular cells Anterior pituitary Inhibits FSH secretion through negative feedback B. Puberty in Males •Sequence of events in which a boy begins to produce male hormones and sperm cells •Begins at 12-14 and ends around 18 •Testosteroneis major male hormone secreted by the testes •Secondary sexual characteristics develop: skin texture, fat distribution, hair growth, skeletal muscle growth, and larynx changes C. Effects of Testosterone Target TissueResponsePenis and scrotum Enlargement and differentiation Hair follicles Hair growth and coarser hair in the pubic area, legs, chest, axillary region, face, and occasionally back; male pattern baldness on the head if the person has the appropriate genetic makeup
Chapter 17: Reproductive System @medtech.files | by MAPB Skin Coarser texture of skin; increased rate of secretion of sebaceous glands, frequently resulting in acne at the time of puberty; increased secretion of sweat glands in axillary regions Larynx Enlargement of larynx and deeper masculine voice Most tissues Increased rate of metabolism Red blood cells Increased rate of red blood cell production; a red blood cell count increase by about 20% as a result of increased erythropoietin secretion Kidneys Retention of sodium and water to a small degree, resulting in increased extracellular fluid volume Skeletal muscle A skeletal muscle mass increase at puberty; average increase is greater in males than in females Bone Rapid bone growth, resulting in increased rate of growth and early cessation of bone growth; males who mature sexually at a later age do not exhibit a rapid period of growth, but they grow for a longer time and can become taller than men who mature earlier D. Male Sexual Behavior and the Male Sex Act •Emission-movement of sperm cells, mucus, prostatic secretions, and seminal vesicle secretions into the prostatic, membranous, and spongy urethra •Ejaculation-forceful expulsion of the secretions that have accumulated in the urethra to the exterior •Orgasm-or climax; occur during the male sex act and result in an intense sensation •Resolution-occurs after ejaculation; penis becomes flaccid, an overall feeling of satisfaction exists, and the male is unable to achieve erection and a second ejaculation •Erection-first major component of the male sex act; neural stimuli cause the penis to enlarge and become firm •Erectile dysfunction -failure to achieve erections •Infertility-reduced or diminished fertility; most common cause in males is a low sperm cell count •Artificial insemination-collecting several ejaculations, concentrating the sperm cells, and inserting them into the female’s reproductive tractV. FEMALE REPRODUCTIVE SYSTEM Consists of: •Ovaries •Uterine tubes/ fallopian tubes •Uterus •Vagina •External genitalia •Mammary glands Functions •Produce female oocytes (sex cells) •Produce female sex hormones •Receive sperm from males •Develop and nourish embryos A. Ovaries ‑primary female reproductive organ ‑produces oocytes and sex hormones ‑one on either side of uterus
Chapter 17: Reproductive System @medtech.files | by MAPB •suspensory ligaments-anchor ovaries to pelvic cavity; extends from each ovary to the lateral body wall •ovarian ligament-attaches the ovary to the superior margin of the uterus •mesovarium- ovarian mesentery where the broad ligament is attached •ovarian follicle-contains oocytes(female sex cell) B. Oogenesis and Fertilization •Oogonia-cells from which oocytes develop •Fertilization-begins when a sperm cell penetrates the cytoplasm of a secondary oocyte •Zygote-has 23 pairs of chromosomes (a total of 46 chromosomes) Oocyte Follicle Fetus oogonium primary oocyte primordial follicle primordial follicle Puberty primary oocyte primary oocyte primary follicle secondary follicle Menopause primary oocyte secondary oocyte mature follicle mature follicle Maturation of the Oocyte and Follicle 1.By the fourth month of development, the ovaries contain 5 million oogonia. 2.By birth, many oogonia have degenerated, and for the remaining oogonia meiosis has stopped in prophase I, causing them to become primary oocytes. 3.By puberty, 300,000 to 400,000 primary oocytes remain, of which about 400 will be released from the ovaries. 4.Ovulationis the release of an oocyte from an ovary. The first meiotic division is completed, and a secondary oocyte is released. 5.A sperm cell penetrates the secondary oocyte, the second meiotic division is completed, and the nuclei of the oocyte and sperm cell are united to complete fertilization. 6.A primordialfollicleis a primary oocyte surrounded by a single layer of flat granulosa cells. 7.In primary follicles, the oocyte enlarges, and granulosa cells become cuboidal and form more than one layer. A zona pellucidais present. 8.In a secondary follicle, fluid-filled vesicles appear, and a thecaforms around the follicle. 9.In a mature follicleor graafian follicle, vesicles fuse to form an antrum, and the primary oocyte is surrounded by cumulus cells.10.During ovulation, the mature follicle ruptures, releasing the secondary oocyte, surrounded by cumulus cells, into the peritoneal cavity. 11.The remaining granulosa cells in the follicle develop into the corpus luteum. 12.If fertilization occurs, the corpus luteum persists. If there is no fertilization, it degenerates. Ovulation-when a mature follicle ruptures, forcing oocyte into peritoneal (pelvic) cavity; due to LH (anterior pit. gland) Corpus luteum-mature follicle after ovulation; degenerates if egg is not fertilized Oogonia → Primary oocyte → Secondary oocyte (outside ovary after ovulation) → + sperm cell → zygote → fetusC. Uterine Tubes ‑aka fallopian tubes oroviduct ‑part of uterus which extends toward ovaries and receive oocytes fimbriae-fringe-like structures around opening of uterine tubes that help sweep oocyte into uterine tubes; surround the surface of the ovary ampulla- part of the uterine tube near the ovary; where fertilization usually occurs implantation-a process where the fertilized oocyte travels to uterus, where it embeds in the uterine wall
Chapter 17: Reproductive System @medtech.files | by MAPB D. Uterus ‑pear sized structure located in pelvic cavity ‑functions: receive, retain, and provide nourishment for fertilized oocyte, where embryo resides and develops ‑supported by broad ligament and round ligament •fundus-part of the uterus superior to the entrance of the uterine tubes •body-main part of the uterus •cervix-narrow region that leads to vagina •cervical canal-opens into the vagina Uterine wall is composed of three layers: •Perimetrium-serous layer; outer layer •Myometrium-muscular layer; middle layer; accounts for the bulk of the uterine wall •Endometrium-inner layer/lining of uterus; consists of simple columnar epithelial cells; sloughed off during menstruation prolapsed uterus- ligaments that support the uterus or muscles of the pelvic floor are weakened E. Vagina ‑internal genitalia ‑extends from uterus to outside of body ‑female copulation organ that receives penis during intercourse ‑allows menstrual flow and childbirth ‑contains very muscular walls and a mucous membrane ‑very acidic to keep bacteria out Hymen-thin membrane covering the vagina F. External Genitalia •Vulva-or pudendum; external female sex organs; consists of mons pubis, labia majora and minora, clitoris, and vestibule •Vestibule-space in which vagina and urethra open •Labia minora-thin, inner folds of skin •Labia majora- two prominent, rounded folds of skin; equivalent to male scrotum •Clitoris-small erectile structure located in vestibule; equivalent to male penis •Prepuce-a fold of skin where 2 labia minora unite over clitoris •Greater vestibular glands- produce a lubricating fluid that helps maintain the moistness of the vestibule •Mons pubis-fatty layer of skin covering pubic symphysis •Pudendal cleft-space between the labia majora •Clinical perineum-region between the vagina and the anus oEpisiotomy-incision in the clinical perineum G. Mammary Glands ‑organs of milk production located in the breasts ‑modified sweat glands ‑female breasts begin to enlarge during puberty ‑consists of lobes covered by adipose ‑lobes, ducts, lobules are altered during lactation to expel milkExternal structures •Areola- a circular, pigmented area that surrounds the nipple •Nipple- very sensitive to tactile stimulation
Chapter 17: Reproductive System @medtech.files | by MAPB Internal structures •Lobes •Lactiferous duct- opens independently to the surface of the nipple •Lobules •Alveoli-secretory sacs •Myoepithelial cells-surround the alveoli and contract to expel milk from the alveoli gynecomastia-condition where the breasts of a male can become permanently enlarged VI. PHYSIOLOGY OF FEMALE REPRODUCTION A. Puberty in Females •begins between 11-13 and is usually completed by 16 •Menarche-first episode of menstrual bleeding •vagina, uterus, uterine tubes, and external genitalia to enlarge and adipose tissue is deposited in breast and hips •elevated levels of estrogen and progesterone are secreted by ovaries B. Menstrual Cycle •Series of changes that occur in sexually mature, nonpregnant females and that result in menses •Menses-a period of mild hemorrhage, during which part of the endometrium is sloughed and expelled from the uterus •Average is 28 daysand results from cyclical changes that occur in endometrium Stages of Menstrual Cycle Days 1-5: Menses(shedding of endometrium) •menstrual bleeding (menses) •estrogen and progesterone levels are low •follicle begins to mature Days 6-13: Proliferative phase(between end of menses and ovulation) •endometrium rebuilds •estrogen levels begin to increase •progesterone levels remain low •follicle matures Day 14: Ovulation•oocyte is released due to LH •estrogen levels high •progesterone levels are increasing •cervical mucus thins Days 15-28 Secretory phase(between ovulation and next menses) •endometrium is preparing for implantation •estrogen levels decrease (low) •progesterone levels high •cervical mucus thickens Endometriosis-a condition in which endometrial tissue migrates from the lining of the uterus into the peritoneal cavity, where it attaches to the surface of organs Blastocyst-a collection of cells when the zygote undergoes several cell divisions (if fertilization occurs) Ectopic pregnancy-if fertilized oocyte (zygote) implants somewhere beside uterus (usually in uterine tube) C. Menopause ‑time when ovaries secrete less hormones and number of follicles in ovaries is low ‑cessation of menstrual cycles ‑menstrual cycle and ovulation are less regular ‑hot flashes, fatigue, irritability may occur ‑estrogen replacement therapy may be used to decreases side effects climacteric-whole time period from the onset of irregular cycles to their complete cessation
Chapter 17: Reproductive System @medtech.files | by MAPB Hormone Secretion HormoneSourceTarget TissueResponseGonadotropin-releasinghormone (GnRH)Hypothalamus Anterior pituitary Stimulates secretion of LH and FSH Luteinizing hormone (LH)Anterior pituitary Ovaries Causes follicles to complete maturation and undergo ovulation; causes ovulation Follicle-stimulating hormone (FSH)Anterior pituitary Ovaries Causes follicles to begin development EstrogenFollicles of ovaries and corpus luteum Uterus Breasts Anterior pituitary and hypothalamus Other tissues Proliferation of endometrial cells Development of mammary glands (duct systems) Positive feedback before ovulation; negative feedback with progesterone on the hypothalamus and anterior pituitary after ovulation Development and maintenance of secondary sexual characteristics ProgesteroneCorpus luteum of ovaries Uterus Breast Anterior pituitary Other tissues Enlargement of endometrial cells and secretion of fluid from uterine glands; maintenance of pregnant state Development of mammary glands (alveoli)Negative feedback, with estrogen, on the hypothalamus and anterior pituitary after ovulation Secondary sexual characteristics OxytocinPosterior pituitary Uterus and mammary glands Contraction of uterine smooth muscle and contraction of cells in the breast, resulting in milk letdown in lactating women Human chorionic gonadotropinPlacenta Corpus luteum of ovaries Maintains corpus luteum and increases its rate of progesterone secretion during the first trimester of pregnancy D. Female Sexual Behavior and Female Sex Act •Female sex drive is partially influenced by testosterone-like hormones produced by the adrenal cortex and estrogen produced by the ovary. •Autonomic nerves cause erectile tissue to become engorged with blood, the vestibular glands to secrete mucus, and the vagina to produce a lubricating fluid. E. Control of Pregnancy Behavioral methods •Abstinence-refraining from sexual intercourse; 100% effective in preventing pregnancy when it is practiced consistently •Coitusinterruptus-or withdrawal; removal of the penis from the vagina just before ejaculation •Natural family planning-requires abstaining from sexual intercourse near the time of ovulation •Lactation- lactation amenorrhea, or LAM; continuous breastfeeding; often stops the menstrual cycle for up to the first 6 months after childbirth; 99% effective Barrier methods -prevent contact between sperm and oocyte •Condom-a sheath made of animal membrane, rubber, or plastic, such as latex; a barrier device that collects the semen •Vaginal condom-or female condom •Diaphragm and cervical cap-flexible latex domes that are placed over the cervix within the vagina odiaphragm cap-larger, shallow latex cup ocervical cap-smaller, thimble-shaped latex cup •Spermicidal agents-foams or creams that kill sperm cells •Intrauterine devices (IUDs) -inserted into the uterus through the cervix Chemical methods -prevent oocyte ovulation •Oral contraceptives-synthetic estrogen and progesterone; among the most effective contraceptives •Mini-pill-an oral contraceptive that contains only synthetic progesterone •Patch (Ortho Evra)-an adhesive skin patch containing synthetic estrogen and progesterone •Vaginal contraceptive ring (Nuva Ring)-inserted into the vagina, where it releases synthetic estrogen and progesterone
Chapter 17: Reproductive System @medtech.files | by MAPB •RU486-or mifepristone; blocks the action of progesterone, causing the endometrium of the uterus to slough off •Morning-after pills-similar in composition to birth control pills Surgical methods -are typically permanent •Vasectomy-a common method used to render males permanently infertile without affecting the performance of the sex act •Tubal ligation-common method of permanent birth control in females; uterine tubes are tied and cut or clamped by means of an incision through the wall of the abdomen •Laparoscopy-an instrument is inserted into the abdomen through a small incision F. Infertility in Females •Causes of infertility in females include malfunctions of the uterine tubes, reduced hormone secretion from the pituitary or ovary, and interruption of implantation VII. EFFECTS OF AGING ON THE REPRODUCTIVE SYSTEM 1.Benign prostatic enlargement affects men as they age, and it blocks urine flow through the prostatic urethra. 2.Prostate cancer is more common in elderly men. 3.Menopause is the most common age-related change in females. 4.Cancers of the breast, the cervix, and the ovaries increase in elderly women. DISEASE AND DISORDERS Condition Description Infectious Diseases Pelvic inflammatory disease (PID) bacterial infection of the female pelvic organs; commonly caused by a vaginal or uterine infection with the bacteria gonorrhea or chlamydiaSexually Transmitted Infections Nongonococcal urethritis inflammation of the urethra that is not caused by gonorrhea; usually due to infection with the bacterium Chlamydia trachomatisTrichomoniasis caused by Trichomonas, a protozoan commonly found in the vagina of women and in the urethra of men; results in a greenish-yellow discharge with a foul odorGonorrhea caused by the bacterium Neisseria gonorrhoeaethat attaches to the epithelial cells of vagina or male urethra and causes pus to formGenital herpes caused by herpes simplex 2 virus; characterized by lesions on the genitals that progress into blister like areas Genital warts caused by a viral infection; very contagious; warts vary from separate, small growths to large, cauliflower-like clustersSyphilis caused by the bacterium Treponema pallidum; multiple disease stages occur; children born to infected mothers may be developmentally delayed Acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV); ultimately destroys the immune system