Human digestive system teeth, and also by the contractions of peristalsis, and segmentation. Gastric acid, and the production of mucus in the stomach, are essential for the continuation of digestion. Peristalsis is the rhythmic contraction of muscles that begins in the esophagus and continues along the wall of the stomach and the rest of the gastrointestinal tract. This initially results in the production of chyme which when fully broken down in the small intestine is absorbed as chyle into the lymphatic system. Most of the digestion of food takes place in the small intestine. Water and some minerals are reabsorbed back into the
Development of the digestive system anterior region (future urogenital sinus). The urorectal septum divides the two regions and breakdown of the cloacal membrane covering this area provides communication to the exterior for the anus and urogenital sinus. The upper part of the anal canal is derived from endoderm of the hindgut. The lower part (one-third) is derived from ectoderm around the proctodeum. Ectoderm, in the region of the proctodeum on the surface of part of the cloaca, proliferates and invaginates to create the anal pit. Subsequently, degeneration of the cloacal membrane establishes continuity between the upper and lower parts of the anal canal. Abnormalities in