- Lesser omentum
Lesser omentum The primitive mesentery of a six weeks’ human embryo, half schematic. (Lesser omentum labeled at left.) Schematic and enlarged cross-section through the body of a human embryo in the region of the mesogastrium, at end of third month. Latin omentum minus Gray's subject #246 1156 MeSH Omentum
The lesser omentum (small omentum; gastrohepatic omentum; omentum minus) is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach and the start of the duodenum.
The lesser omentum is extremely thin, and is continuous with the two layers of peritoneum which cover respectively the antero-superior and postero-inferior surfaces of the stomach and first part of the duodenum.
When these two layers reach the lesser curvature of the stomach and the upper border of the duodenum, they join together and ascend as a double fold to the porta hepatis.
To the left of the porta, the fold is attached to the bottom of the fossa for the ductus venosus, along which it is carried to the diaphragm, where the two layers separate to embrace the end of the esophagus.
At the right border of the lesser omentum, the two layers are continuous, and form a free margin which constitutes the anterior boundary of the epiploic foramen.
Anatomically, the lesser omentum is divided into ligaments, each starting with the prefix "hepato" to indicate that it connects to the liver at one end.
Most sources divide it into two parts:
- hepatogastric ligament: the portion connecting to the lesser curvature of the stomach
- hepatoduodenal ligament: the portion connecting to the duodenum
- hepatophrenic ligament: the portion connecting to the thoracic diaphragm
- hepatoesophageal ligament: the portion connecting to the esophagus
Between the two layers of the lesser omentum, close to the right free margin, are the hepatic artery, the common bile duct, the portal vein, lymphatics, and the hepatic plexus of nerves—all these structures being enclosed in a fibrous capsule (Glisson's capsule).
Between the layers of the lesser omentum, where they are attached to the stomach, run the right and left gastric arteries, as well as the gastric veins.
- ^ abdominalcavity at The Anatomy Lesson by Wesley Norman (Georgetown University) (peritoneumonsagcut, xsectthrulesseromentum)
- ^ SUNY Labs 38:st-0304 - "Stomach, Spleen and Liver: Ligaments"
- ^ SUNY Labs 37:05-0103 - "Abdominal Cavity: The Lesser Omentum"
- SUNY Figs 37:04-01 - "The stomach and lesser omentum."
- SUNY Labs 37:05-0100 - "Abdominal Cavity: The Lesser Omentum"
- SUNY Labs 38:03-0102 - "Stomach, Spleen and Liver: Contents of the Hepatoduodenal Ligament"
- SUNY Anatomy Image 7823
- SUNY Anatomy Image 8147
- Anatomy at UMich peritoneal_dev_module/peritoneal_06
Abdominopelvic cavity: Abdomen/Abdominal cavity and Pelvis/Pelvic cavity and Peritoneal cavity (TA A10, TH H3.04.08, GA 4.408 and GA 11.1147) Extraperitoneal spaceRetroperitoneal space · Retropubic space Peritoneal ligaments,
mesenteries, and foldsAbdominalFrom ventral mesenteryFrom dorsal mesenteryUmbilical folds (Supravesical fossa, Medial inguinal fossa, Lateral umbilical fold, Lateral inguinal fossa) · Ileocecal foldGeneralUrogenital peritoneumUterus/ovariesRecesses
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