Two muscles of the head are frontalis and mentalis. The mentalis muscle located at the lower end of the chin. It acts as a primary muscle of the lower lip. The mentalis muscle originates from the mandible. It provides stability to the lower lip to allow it to pout. That causes protrusion of the lower lip and it raises the skin of the chin. When the lower chin rises it causes in the elevation and wrinkling of the chin’s skin.
The frontalis muscle is a thin muscle that is attached closely to superficial fascia. It has no bony attachments. It is located at the front of the head and raises eyebrows and wrinkles. It originates at the gelea aponeurotica, the insertion is the skin and muscles around the eye. The primary function of the frontalis
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The deltoid is located on the outer aspect of the shoulder in a triangular shape. It originated from a lateral one-third of the acromion, clavicle and spine of scapula to deltoid tubercle. The insertion of the deltoid is tuberosity of the humerus. The deltoid muscle is responsible for all arm rotation allowing us to carry things at a safe distance away from the body. It also stops dislocation and injury from carrying heavy objects.
One muscle of the trunk is the external intercostal. The external intercostals is responsible for forced and quiet inhalation, raising the ribs ad expanding the chest cavity. The external intercostals originated for the interior border of the ribs as far back as posterior angles. Its insertion is superior border of the ribs, passing obliquely backwards and downwards. Its function is to fix intercostal spaces during respiration by elevating the ribs.
One muscle of the lower extremity is the iliacus. The iliacus muscle is located in the lower portion of the trunk. It is covered in a thick connective tissue. The muscle is shaped like a triangle, flat with an exact fit. It originates for the iliac fossa within the abdomen. Its insertion is the lowermost surface of the lesser trochanter of femur. Its function is to flex the medially and rotates the