Small and Large Intestine: Introduction

00:02 In other lectures, I have described the histology of organs in the oral cavity that have an important role in the digestive system. And I've also described the histological structure of the esophagus and the stomach and their important role in the digestive system.

00:22 In this lecture, you are going to learn about the histology of the small intestine and the large intestine. At the end of the lecture, I'd like you to understand the components of the wall of the small intestine and the large intestine, and the components, particularly, the mucosa that is specialized for the various functions these two organs carry out.

00:48 I'm also going to introduce to you some components of the diffuse neuroendocrine system, and also components of the gut-associated lymphoid tissues, and also the enteric nervous system.

01:05 The small intestine is specialized to actually absorb all the products that are digested or broken down in the lumen from the secretions of enzymes from various parts of the body.

01:21 Those digestive products are then absorbed across the wall of the small intestine and carried to the liver in the portal vein. The large intestine actually stores unwanted or undigested products, and then finally eliminates them as feces. In this organ, there is a lot of water absorption. So the mucosa of the large intestine is really specialized for water absorption. Also, because the whole gut tube, the lumen of the gut is exposed to the exterior, it will contain various pathogens. So, I just want to make sure that we explain and you're aware of the function of the gut in trying to combat those pathogens, identify them, and alert the immune system.