From the stomach the foods are pass into the small intestine for final digestion. The small intestine is compose of three parts. These three parts are the duodenum ( the upper 20 centimeters long tube that is connected to the stomach), the other part is the jejunum ( 2.5 meters long) and the other part is the ileum ( the longest half coiled through the abdominal cavity).
The small intestine has a big surface area, probably used for absorption of molecules in a very large amount. The surface area for absorption was increase by the folds of the mucosa (membranous lining and the presence of villi).
The villi are the tiny finger like projections which comes out from the mocusal folds. Every single villus contains an epithelial cells for covering. It also contains vessels that scattered within.
The surface area of the small intestine was added by the presence of micro-villi (a tinier projections) some digestive enzyme also produced by the cells of the intestinal epithelium.
Peptidases is one of the enzymes secreted by the cells of the intestinal epithelium. The peptidases breaks short polypeptides into amino acids. Another enzymes is the Maltase. Maltase breaks down maltose to become glucose molecules. Other enzymes where also produce such as sucrase and lactase.
The foods undergoes digestions first in the mouth. Then it passes through the esophagus passing through it through peristalsis, and goes into the stomach. There the foods are further digested and passes into the small intestine. In the small intestine, the final digestion and absorption takes place wherein nutrients are absorbed by the body and waste are segregated.