Figure 12.3: Physiological anatomy of the stomach    

d.Small intestine: It comprises three parts viz. duodenum, jejunum and ileum. Due to its small diameter, it is named so. The length of small intestine is correlated with the height of person but not with the weight. It is about 6.25 meters long. Thus, it is the longest part of alimentary tract. Chyme is conducted through small intestine by peristaltic movement. When chime stretches the intestinal wall, it elicits localized concentric contractions spaced at intervals cause segmentation of small intestine. In such a way chyme moves toward the anus at a speed of 0.5 to 2.0 cm/s. Movement in proximal parts is faster than terminal portion. During movement of chyme through small intestine complete digestion of proteins, carbohydrates, fats and nucleic acids occurs.

e.Large intestine: Its diameter is always larger than small intestine but it varies from one region to another. It is about 1.5 m long. It is divided into three parts: cecum, colon and rectum. Cecum is a pouch type structure. The outgrowth of cecum is a vestigial body known as vermiform appendix. The cecum is more developed in