Introduction

This topic covers the structure and function of the stomach, small and large intestines, and other tissues important for digestion: the liver, pancreas and gall bladder. After following this topic you should know how the structure of the stomach, small and large intestine varies, and how this is related to function, the roles of the liver, pancreas and gall bladder in digestion, and how their structure is related to function.

Objectives

After following this topic you should know:

1. How the basic arrangement of the tissue in the walls of the digestive tract varies in response to the differing functions of the different parts of the tract.
2. The relationship between structure and function for the different layers of the GI tract, mucosa, submucosa and muscularis externa, and their arrangement in each part of the alimentary tract: stomach, small and large intestines, and the appendix. (The oesophagus was covered in the topic 'Oral, Oesophagus').
3. The appearance, organisation and functions of the epithelial cells lining the alimentary tract and in the gastric glands, crypts of Lieberkuhn and Brunner's glands, and to understand the specialisations in the gut that enable absorption, and the distribution of lymphoid tissue in the GI tract.
4. The structure and function of glands associated with the digestive tract: liver, gall bladder and pancreas. (Salivary glands are covered in the topic 'Oral, Salivary glands')
5. How to recognise and describe the histological structure and function of liver lobules, and what the relationship is, within liver lobules, between hepatocytes, spaces of Disse, sinusoid lining cells and sinusoids, how blood and bile pass through the liver lobules and how this is related to hepatocyte function.