Oment

The oment, or omentum, is a double-layered fold of peritoneum in the abdomen that connects the stomach with other organs. There are two main components: the greater omentum and the lesser omentum. Each serves distinct anatomical and functional roles within the peritoneal cavity.

The lesser omentum extends from the lesser curvature of the stomach and the proximal duodenum to the liver. It contains the hepatogastric and hepatoduodenal ligaments, within which run the portal triad: the hepatic artery proper, the portal vein, and the common bile duct. The hepatoduodenal ligament forms the anterior boundary of the epiploic foramen (the opening to the lesser sac), separating the liver from the stomach and duodenum.

The greater omentum hangs from the greater curvature of the stomach and the first part of the duodenum, draping over the transverse colon and the small intestine. It consists of multiple folds of peritoneum that can accumulate substantial adipose tissue. The greater omentum contains immune components, including milky spots with macrophages, and is notable for its ability to migrate to sites of inflammation or injury, where it can adhere to and help seal perforations or limit the spread of intra-abdominal infection. It also provides fat storage, insulation, and mechanical protection for abdominal organs.

Developmentally, the greater omentum arises from the dorsal mesogastrium, while the lesser omentum originates from the ventral mesogastrium. Clinically, the omenta are encountered in abdominal surgery and can participate in conditions such as omental infarction or torsion; they may also be mobilized or used in reconstructive procedures due to their rich vascular supply and immunologic components.