lesser omentum [AS, losian, to lose; L, omentum, entrails] , a membranous extension of the peritoneum from the peritoneal layers covering the ventral and the dorsal surfaces of the stomach and the first part of the duodenum. The lesser omentum extends from the portal fissure of the liver to the diaphragm, where the layers separate to enclose the end of the esophagus. It also forms two ligaments, one associated with the liver, the hepatogastric ligament, and the other, the hepatoduodenal ligament, with the duodenum. Also called gastrohepatic omentum, small omentum.
