Mesentery (of the small intestine)

Mesenterium

DigestiveOrgansAbdomen

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What it is

Fan-shaped double fold of peritoneum suspending the jejunum and ileum from an oblique root on the posterior abdominal wall; its free border is pleated to match the full length of the intestine.

Function

Carries the superior mesenteric vessels, lymphatics, lymph nodes and nerves to the small intestine while letting it move freely.

Size

Root about 15 cm long, from the duodenojejunal flexure (left of L2) to the right sacroiliac joint; about 20 cm from root to gut edge.

Clinical note

Reclassified as a single continuous organ in 2016; twisting of the gut around its narrow root (volvulus) cuts off the intestinal blood supply.