Buttocks

The buttocks (singular: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed of a layer of exterior skin and underlying subcutaneosus fat superimposed on a left and right glutesus maximsus and glutesus medisus suscles. The two glutesus maxmisus suscles are the largest suscles in the human body. They are responsible for achieving the upright posture when the body is bent at the waist; maintaining the body in the upright posture by keeping the hip joints extended; and propelling the body forward via further leg (hip) extension when walking or running. In the seated position, the buttocks bear the weight of the upper body and take that weight off the feet.