Anatomy & Physiology - Human Body
Human body is one of the most complex structures. It has billions of microscopic parts that work together in perfect harmony. The human body consists of billions of smaller structures. These are of four major types:
Cell
A Cell is the smallest unit of human body which is self-sustainable and is capable of reproducing itself. The origin of human body is a newly fertilized cell that gets developed in numerous and different types of cells. The human body consists of approximately 100 trillion cells the basic unit of life. These cells are organized biologically to ultimately form the whole body.
Tissues
Tissues are complex units made up of a group of numerous similar cells that together carry out a specific function. The study of tissue is known as histology, whereas, in connection with disease it is known as histopathology.
Organs
An organ is a collection of tissues joined in a structural unit to perform a common function. An organ consists of different types of tissues. For example, the muscular tissue in the heart is the myocardium, while other types of tissues include the nerves, blood and connective tissues.
Systems
The entire structure of a human body comprises of a head, neck, torso, two arms and two legs. There are various systems that are made up of varying numbers and types of organs arranged together to perform complex functions for the body. There are nine major systems that help human body perform various functions. These are: