Superior mesenteric artery

Arteria mesenterica superior

CardiovascularBlood vesselsAbdomen

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What it is
Leaves the front of the aorta at L1, about 1 cm below the coeliac trunk, passes behind the neck of the pancreas and over the left renal vein and third part of the duodenum, then runs down in the root of the mesentery towards the right iliac fossa, giving jejunal, ileal and colic branches.
Function
Supplies the midgut: the duodenum beyond the bile duct, jejunum, ileum, caecum, appendix, ascending colon and two-thirds of the transverse colon.
Size
~6–8 mm diameter; ~20 cm long.
Clinical note
Sudden blockage (usually an embolus) causes acute mesenteric ischaemia with pain out of proportion to the examination findings; the narrow aorto-mesenteric angle can squeeze the duodenum or left renal vein ("nutcracker").

Nearby cardiovascular structures Abdominal aorta, Common hepatic artery, Hepatic portal vein, Inferior mesenteric artery, Left renal artery, Left renal vein, Right renal artery, Right renal vein, Splenic vein, Superior mesenteric vein