Intestines (An Overview)

The intestines are divided into two major segments - the small intestine and the large intestine, and like the entire gastrointestinal system, consists of five layers of tissue - the serosa or outer-most layer, the circular muscle and the longitudinal muscle which are the layers responsible for the wave-like muscular contraction of smooth muscle known as peristalsis, the submucosa, and the mucosa which contains roughly four million microscopic finger-like projections called intestinal villi which because of their shape, can increase surface area for digestion and absorption of nutrients.