Omentum

A sheet of fat that is covered by peritoneum. The greater omentum is attached to the bottom edge of the stomach, and hangs down in front of the intestines. Its other edge is attached to the transverse colon. The lesser omentum is attached to the top edge of the stomach, and extends to the undersurface of the liver.

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A fold of peritoneum passing from the stomach to another abdominal organ. [L. the membrane that encloses the bowels]

- gastrocolic o. SYN: greater o..

- gastrohepatic o. SYN: lesser o..

- gastrosplenic o. SYN: gastrosplenic ligament.

- greater o. [TA] an areolar, four-layer peritoneal fold, formed by the double-layer dorsal mesentery of the stomach (dorsal mesogastrium) descending from the greater curvature of the stomach to fold under on itself and ascend to the transverse colon; the descending and ascending portions fuse, obliterating the inferior recess of the omental bursa, resulting in the four-layer structure that usually hangs over the anterior aspect of the intestines like an apron; components include the following peritoneal ligaments: gastrophrenic, gastrosplenic, splenorenal, and gastrocolic. SYN: o. majus [TA], caul (2), cowl, epiploon, gastrocolic o., pileus, velum (3).

- lesser o. [TA] a thin, double-layer peritoneal fold formed by the ventral mesentery of the stomach (ventral mesogastrium) passing from the lesser curvature of the stomach and upper border to the proximal duodenum (2 cm distal to the pylorus) to the liver (margins of the porta hepatis and into the depth of the fissure of the ductus venosus); major subcomponents include the hepatogastric ligament (main sheetlike portion) and the hepatoduodenal ligament (thickened free right border, which encloses the hepatic artery, portal vein, and common bile duct. SYN: o. minus [TA], gastrohepatic o., omentulum.

- o. majus [TA] SYN: greater o..

- o. minus [TA] SYN: lesser o..

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omen·tum ō-'ment-əm n, pl -ta -ə or -tums a fold of peritoneum connecting or supporting abdominal structures (as the stomach and liver) see GREATER OMENTUM, LESSER OMENTUM

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n.

a double layer of peritoneum attached to the stomach and linking it with other abdominal organs, such as the liver, spleen, and intestine. The great omentum is a highly folded portion of the omentum, rich in fatty tissue, that covers the intestines in an apron-like fashion. It acts as a heat insulator and prevents friction between abdominal organs. The lesser omentum links the stomach with the liver.

• omental adj.

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omen·tum (o-menґtəm) pl. omenґta [L. “fat skin”] a fold of peritoneum extending from the stomach to adjacent organs in the abdominal cavity; see o. majus and o. minus. Called also epiploon. omental adj