The small intestine has three sub-regions:
- Duodenum: C- shaped
- Jejunum: A long coiled middle portion
- Ileum: Highly coiled. It opens in the large intestine.
Villi are supplied with a network of capillaries and a large lymph vessel called the lacteal.
Mucosa epithelium has goblet cells. They secrete mucus which helps in lubrication. Mucosa also forms crypts in between the bases of villi in the intestine (crypts of Lieberkuhn).
- It serves for both digestion and absorption.
- It receives two digestive juices; the bile and pancreatic juice.
- Ileum is very long, has large villi and made up of single epithelium, which helps in absorption of food.