Small Intestines

The small intestine leads from the stomach to the large intestine. It consists of three segments: the duodenum, the jejunum and the ileum. Its total length is 20 feet, and its diameter varies between 2.5 and 4 cm. The small intestine is a hollow muscular tube. It has transverse (across its width) folds called plica. These plicae are covered with little fingerlike projections called villi. The plicae and the villi serve to increase the surface area of the small intestine, so that there is greater absorptive area. The more absorption occurring in a section of intestine, the more plicae and villi will be present.