Digestive system: Intestine.

The intestines are the parts of the digestive system responsible for the absorption of nutrients and water. Two anatomic regions exist, the small intestine and the large intestine. Both of these are further subdivided into anatomically discernible subdivisions. The small intestine has three parts: the duodenum, the jejunum, and the ileum; the large intestine is subdivided into the colon, cecum, rectum, and is continuous with the anus, the last portion of the alimentary canal  

This diagram lays out in schematic form some of the salient features of the two major subdivisions of the intestine, and highlights their similarities and differences. These are key things that will enable you to distinguish them from each other in the microscope. Overall the intestines have the normal form expected of tubular organs, including the four "tunics" discussed in Exercise 18, the tunica mucosa, tunica submucosa, tunica muscularis externa, and the tunica serosa.

Author. Dr. Thomas Caceci.
www.vetmed.vt.edu.