The superior mesenteric artery (SMA) is one of the three non-paired arteries that provide blood to the gut and other abdominal viscera.
Single vessel arising anteriorly from abdominal aorta at the level of L1.
Courses anteroinferiorly, behind the neck of pancreas and splenic vein, crossing anterior to the left renal vein. It emerges anterior to the uncinate process of the pancreas and crosses anterior to the third part of duodenum. It then enters the upper portion of the small bowel mesentery and runs along the root of the mesentery downwards to the right. Branches to the jejunum and ileum are given off to the left, and branches to the proximal and mid colon are given off to the right.
The SMA terminates at the ileum where it anastomoses with the ileal branch of the ileocolic artery. Some anatomists believe the ileocolic artery is the terminal portion of the SMA and that what many consider the terminal SMA is the last of the ileal branches.
- jejunal branches
- ileal branches
Inferior pancreaticoduodenal artery
The first branch of the SMA, though it often arises from the first jejunal branch. Anastomoses with branches of the superior pancreaticoduodenal artery (from the gastroduodenal artery). Supplies the head of the pancreas and the duodenum distal to the ampulla of Vater.
Jejunal and ileal branches
Variable in number. Pass in the two layers of the mesentery to the jejunum and ileum. They progressively divide and join in a series of anastomosing arcades. From the arcades, straight arteries (also known as vasa recta) pass to the small bowel.
Runs obliquely to the ileocaecal junction. It divides into an ileal branch that supplies the terminal ileum and anastomoses with the terminal SMA, and a colic branch that supplies the proximal ascending colon and anastomoses with the descending branch of the right colic artery. It also gives off anterior and posterior caecal arteries, one or both of which gives off an appendicular artery.
Right colic artery
May arise directly from the SMA but often arises from a common trunk with the ileocolic artery or middle colic artery. Courses to the right to the ascending colon. Divides into a descending branch that supplies the lower portion of the ascending colon and anastomoses with the colic branch of the ileocolic artery, and an ascending branch which supplies the upper portion of the ascending colon and anastomoses at the hepatic flexure with the right branch of the middle colic artery.
Middle colic artery
Passes in the layers of the transverse mesocolon to the transverse colon. Divides into a right branch that supplies the right portion of the transverse colon and anastomoses at the hepatic flexure with the ascending branch of the right colic artery, and a left branch that supplies the left portion of the transverse colon and anastomoses at the splenic flexure with the left colic branch of the IMA.
Marginal artery of Drummond
The terminal branches of the ileocolic, right colic and middle colic arteries - along with the terminal branches of the left colic artery and sigmoid branches of the IMA - form a continuous arterial circle or arcade along the inner border of the colon known as the marginal artery of Drummond. From this marginal artery, straight vessels (also known as vasa recta) pass to the colon.
The SMA is the artery to the midgut. It supplies the gut from the ampullary region of the 2nd part of the duodenum to the splenic flexure. The inferior pancreaticoduodenal artery also supplies the head of the pancreas.
- replaced right hepatic artery
- accessory right hepatic artery
- replaced common hepatic artery
- replaced splenic artery
- replaced left gastric artery
- replaced dorsal pancreatic artery
- coeliaco-mesenteric trunk
- arc of Buhler
- arc of Riolan
Synonyms & Alternative Spellings
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|Superior mesenteric artery (SMA)||✗|