Overview
Branch of the abdominal aorta supplying structures derived from embryological midgut.
- The foregut extends from the mouth to the major duodenal papilla (where the ampulla of Vater empties into the duodenum).
- The midgut extends from this point to the proximal two thirds of the way along the transverse colon.
- The hindgut runs from the distal third of the transverse colon to the dentate line of the anal canal
Origin
Anterior branch of abdominal aorta at L1, just below coeliac trunk (T12), behind neck of pancreas and splenic vein
Course
- Descends anteriorly to the right, anterior to left renal vein, and posterior to neck of pancreas and splenic vein
- Passes anterior to uncinate process of pancreas and third part of duodenum
- Enters the root of the small bowel mesentery to descends toward ileocecal junction, to the left of the superior mesenteric vein
- Mesenteric root – origin of the mesentery of the jejunum and ileum from the posterior parietal peritoneum. It descends from the duodenojejunal flexure at a 45 degree angle to the ileocaecal junction in the right iliac fossa. It crosses over the third part of the duodenum, abdominal aorta, inferior vena cava, right ureter and right psoas major muscle.
Termination
Terminates at the ileum by anastomosing with ileal branch of ileocolic artery
Branches
- Inferior pancreaticoduodenal artery – anterior and posterior branches, ascends on corresponding sides of head of pancreas to anastomose with superior pancreaticoduodenal arteries to supply pancreas and duodenum
- Jejunal and ileal arteries – left branches, numerous branches supplying jejunum and ileum, passes between layers of the mesentery, forms anastomosing arcades then vasa recta to the walls of small bowel
- Middle colic artery – right branch, enters transverse mesocolon, right branch anastomoses with right colic artery to supply hepatic flexure, left branch anastomoses with left colic artery to supply right two thirds of transverse colon
- Right colic artery – right branch, passes to the right retroperitoneally to ascending colon, ascending branch anastomoses with middle colic artery and descending branch anastomoses with ileocolic artery to supply ascending colon
- Ileocolic artery – right branch, descends toward right iliac fossa
- Superior branch anastomoses with right colic artery to supply ascending colon
- Inferior branch divides into colic, caecal, appendicular and ileal branches to supply terminal ileum, caecum and appendix
- Marginal artery of Drummond– The terminal branches of the superior mesenteric artery (middle colic, right colic and ileocolic arteries) and inferior mesenteric artery (left colic and sigmoid arteries) anastomose to form a continous arterial circle (arcade) that runs along the mesenteric border. It may supply collateral flow between the superior and inferior mesenteric artery circulations. From this marginal artery, straight vessels (also known as vasa recta) pass to the colon.
Relations
- Accompanied on its right by superior mesenteric vein
- Crosses inferior vena cava, psoas major and ureter
Variants
- Replaced branches of coeliac artery
- Common coelicomesenteric trunk
- Common coeliaco-bimesenteric trunk
- Arc of Riolan (mesenteric meandering artery of Moskowitz or central anastomotic mesenteric artery) – inconstant arterioarterial anastomosis between the superior and inferior mesenteric arteries.
- Arc of Buhler – persistent embryonic anastomotic branch between the 10th and 13th ventral segmental arteries, resulting in a connection between the coeliac trunk and superior mesenteric artery that provides collateral pathway between two vascular territories (1 – 4%). The arch is independent of both the gastroduodenal and dorsal pancreatic artery.