Structure
The lesser omentum is a double layer of peritoneum derived from the ventral mesogastrium. It runs from the inferior surface of the liver to the lesser curvature of the stomach and the superior surface of the first part of the duodenum. It’s extremely thin and is continuous with the peritoneum that covers the anterosuperior and posteroinferior surfaces of the stomach and the first part of the duodenum.
Related parts of the anatomy
Anatomical Relations
For descriptive purposes, the lesser omentum is arbitrarily divided into two parts: the hepatoduodenal ligament and hepatogastric ligament.
The section of the lesser omentum that runs from the liver to the stomach is called the hepatogastric ligament. The section that runs from the liver to the first part of the duodenum is called the hepatoduodenal ligament. Occasionally a portion of the lesser omentum also extends from the liver to the abdominal esophagus and is called the hepatoesophageal ligament.
The left and right gastric vessels, branches of the vagus nerve, and lymph nodes are located within the two layers of the hepatogastric ligament near the lesser curvature of the stomach.
The right edge of the lesser omentum surrounds the contents within the “portal triad,” which includes the portal vein, the bile duct, and the hepatic artery proper, along with associated autonomic nerves and lymphatics. This right edge also serves as the anterior border of the omental (epiploic) foramen, which connects the greater sac and the omental bursa (lesser sac) of the peritoneal cavity.
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Lesser Omentum
The lesser omentum, also called the small omentum or gastrohepatic omentum, is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach (hepatogastric ligament) and the first part of the duodenum (hepatoduodenal ligament).