It consist of three sections: the duodenum, which id about 25cm long; the jejunum, which is about 2mlong; and the ileum, which is about 5m long. In total the small intestine measures about7.25m in length.
The mucus(inner-most lining) of the small intestine posses numerous villi. A villus is a tiny, finger-like projection whose wall is richly supplied with blood capillaries and llumph vessels. The mucosa also has glangs which secrete intestinal fluid. This fluid is a mixture of mucus and enzymes. The pH of the fluid is about 7-8(that is alkaline). This is favorable for the intestinal enzymes.
Fig TS of human small intestine show the structure of villus