(b) Liver : It is the largest gland in the body, situated in contact with the stomach. The human liver is imperfectly bilobed. Between the lobes lies a green sac-like structure called the gall bladder which stores the secretion of liver (called bile). The hepatic duct from the liver lobes and the cystic duct from the gall bladder join to form the common bile duct.

(c) Pancreas : It is an elongated lobulated gland situated in the loop of the duodenum. The pancreatic duct joins the common bile duct and opens into the duodenum.

The wall of the alimentary canal is made up of concentric layers of serosa, (outermost), muscularis, sub-mucosa and mucosa, (innermost). According to the function of the part, they are modified as described below:

Histology of stomach: A transverse section of stomach shows four concentric layers as described below :

Figure 16.10 (A) Transverse Section (B) Single gastric gland

(i) Serosa : It is the outermost single layer of cells.

(ii) Muscularis : It is comparatively thick and distinguished into outer layer of longitudinal muscles, middle thick layer of circular muscles and inner layer of oblique muscles.

(iii) Sub-mucosa : It is a spongy layer situated between the mucosa and muscularis. It contains blood vessels and nerve endings. Between the sub-mucosa and mucosa, there is a distinct layer of muscularis mucosa.

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Table of Contents

16.0 - Introduction
16.1 - Nutritional Requirements, Imbalances and Deficiency Diseases
16.2 - Organs of Digestion and Physiology of Digestion

Chapter 17