Greater omentum

Greater omentum
The greater omentum and corresponding vasculature is visible covering the intestines (dissection image with liver held out of the way). Label at bottom.
Details
Precursor	Dorsal mesentery
Identifiers
Latin	omentum majus
MeSH	A01.047.025.600.573
TA	A10.1.02.201
FMA	9580
Anatomical terminology []

The greater omentum (also the great omentum, omentum majus, gastrocolic omentum, epiploon, or, especially in animals, caul) is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature of the stomach, passing in front of the small intestines and doubles back to ascend to the transverse colon before reaching to the posterior abdominal wall. The greater omentum is larger than the lesser omentum, which hangs down from the liver to the lesser curvature. The common anatomical term "epiploic" derives from "epiploon", from the Greek epipleein, meaning to float or sail on, since the greater omentum appears to float on the surface of the intestines. It is the first structure observed when the abdominal cavity is opened anteriorly.

The greater omentum is the largest of the two peritoneal folds. It consists of a double sheet of peritoneum, folded on itself so that it has four layers.

The two layers of the greater omentum descend from the greater curvature of the stomach and the beginning of the duodenum. They pass in front of the small intestines, sometimes as low as the pelvis, before turning on themselves, and ascending as far as the transverse colon, where they separate and enclose that part of the intestine.

These individual layers are easily seen in the young, but in the adult they are more or less inseparably blended.

The left border of the greater omentum is continuous with the gastrosplenic ligament; its right border extends as far as the beginning of the duodenum.

The greater omentum is usually thin, and has a perforated appearance. It contains some adipose tissue, which can accumulate considerably in obese people.