The gastrointestinal (GI) tract

Published on April 28, 2021   19 min
My name is Richard Drake, and I'm Director of Anatomy and Professor of Surgery at the Cleveland Clinic, Lerner College of Medicine at Case Western Reserve University. Today I'm going to talk to you about regional anatomy, and my specific topic is: The Abdomen 3 - GI Tract.
I'm going to begin with talking in general terms about the abdominal viscera, and give a few examples and define the peritoneum, the omenta, and the mesenteries, just so everyone is clear on the descriptions of these structures. Peritoneum is a membrane that lines the abdominal cavity, and then reflects out onto the organs. Mesenteries are two-layered structures (that are usually carrying blood vessels) that suspend the organs, and the omenta are types of mesentery. The next slide shows you some pictures.
In this slide, we have some very basic examples of what the peritoneum is. As you can see, the parietal peritoneum is what is lining the abdominal wall, on the inside of the cavity. The visceral peritoneum is what is specifically lining the organs. Here you can see that one of the organs is suspended by a mesentery, which is a two-layered structure usually containing blood vessels.
The next slide gives you an example of what happens when an organ becomes retroperitoneal (meaning it's back up against the posterior abdominal wall), and the parietal peritoneum moves off it, over the organ, and then back to the floor again. This is an appearance of an organ that is retroperitoneal. We still have visceral peritoneum around the organ, and parietal peritoneum lining the wall. Looking at the next slide,