Answer
The mesenteries are connective tissue sheets that suspend the digestive tract organs in the peritoneal cavity. This loose suspension facilitates movements of the digestive organs which are integral to their mixing and digestive functions. Also the mesenteries prevent the long small intestine from becoming twisted and tangled. Furhermore, blood vessels, nerves, and lymphatic and lymphod elements that supply the digestive organs find a path and support in the sheets of the mesenteries.
The parietal peritoneum lines the wall of the abdominal cavity . Ventrally, it turns into the posterior/dorsal mesentery that splits into two layers on contact with organs; these layers of tissue surround these organs as their serosal covering. On the ventral side of digestive organs these serosal sheets unite to form the ventral or anterior mesentery which my attach to the anterior abdominal wall (or to other organs); alterantively, the anterior mesentery may just hang loose in the abdominal cavity.
Anterior mesenteries:
The lesser and the greater omenta are anterior messenteries that are closely associated with the stomach:
The lesser omentum extends from the liver to the lesser curvature of the stomach :
the greater omentum hangs loosely from the greater curvature ( left margin) of the stomach like an apron covering the small intsetine.
The mesocolon is the part of the greater omentum that anchors the colon to the abdominal wall
Intraperitoneal and retroperitoneal organs:
Organs that are enclosed by mysentery on both sides are described as intraperitoneal, that is, they are considered to be within the peritoneal cavity. However, if an organ lies against the dorsal body wall and is covered by peritoneum only on its ventral surface, it is considered to be outside the peritoneal cavity and is designated a retroperitoneal organ .
Work Step by Step
Examples of intraperitoneal organs are liver, gall bladder, spleen, transverse colon, sigmoid colon, and male bladder. Some retroperitoneal organs are pancreas, adrenal glands, kidneys,duodenum, descending colon, aorta, inferior vena cava, and ureters
