Painting of Villi:Small intestine duodenum with numerous tongue-shaped projections (villi) protruding from the gut wall. The duodenum is the first part of the small intestine, extending after the stomach to the jejunum. As a major secretory region of the gut, the duodenum also receives secretory products from other organs to aid in digestion. As in other parts of the small intestine, digestion and absorption are maximized by the large surface area conferred by the presence of villi. The villi are composed mainly of columnar epithelial cells, each of which is covered with many microvilli to increase cell absorption (not seen). Globlet cells are present among the epithelial cells (not seen). They secrete mucus that lubricates the lining of the intestine.