Peritoneum, Mesentery and Omentum

• Parietal peritoneum lines the abdominal wall
• Visceral peritoneum lines the organs
• Between the two lies the peritoneal cavity
• Reflections of the parietal peritoneum between organs are called ligaments (e.g., hepatoduodenal ligament)
• Ligaments that connect the stomach to other organs are called omenta.
• Mesentery connects the bowel to the posterior abdominal wall.
• All of these contain fat, blood vessels, lymphatics and nerves.

Greater Omentum

• Extends inferiorly from the greater curvature of the stomach and folds over to insert into the T. colon
• On CT, it is the fatty area behind the anterior abdominal wall

Lesser Omentum

• Extends between the lesser curvature of the stomach and the liver

Small Bowel Mesentery

• Fan shaped
• Connects jejunum and ileus to the posterior abdominal wall
• Root is at duodenojejunal junction
• It contains SMA and branches
• On CT, it is seen to contain fat and blood vessels