Colon (anatomy)

From Freepedia

In anatomy of the digestive system, the colon or large intestine or large bowel is the part of the intestine from the cecum to the rectum. Its primary purpose is to extract water from feces. In mammals, it consists of the cecum, ascending colon and approximately the first two-thirds of the transverse colon on the right (or proximal) side and the last third of the transverse colon to the splenic flexure, the descending colon, the sigmoid colon, and the rectum on the left (or distal) side.

Diseases of the colon

angiodysplasia of the colon
colitis
colon cancer
constipation
Crohns disease
diarrhea
diverticulitis
Hirschsprung's disease (aganglionosis)
irritable bowel syndrome (spastic colon)
polyposis (see also Polyp)
pseudomembranous colitis
ulcerative colitis and toxic megacolon

Role in digestion

The large intestine comes after the small intestine in the digestive tract and measures approximately 1.5m in length. Although there are differences in the large intestine between different organisms, the large intestine is mainly responsible for storing waste, reclaiming water and maintaining the water balance and absorbing some vitamins, such as vitamin K.

By the time the chyme has reached this tube, almost all nutrients have been absorbed by the body and only water and some electrolytes like sodium and chlorine are left. As the chyme moves through the large intestine, water is removed, while the chyme is mixed with mucus and bacteria, and becomes feces. The large intestine produces no digestive enzymes — chemical digestion is completed in the small intestine before the chyme reaches the large intestine. The pH in the colon varies between 5.5 and 7 (neutral or slightly acidic).

Digestive system