Which artery supplies the small intestine?

• A. Celiac trunk
• B. Inferior mesenteric artery
• C. Renal artery
• D. Superior mesenteric artery

Answer: (D)

Arterial supply to the gut follows embryologic divisions, and the small intestine comes from the midgut, so its primary blood supply is the superior mesenteric artery. The SMA branches off the aorta below the celiac trunk and sends many jejunal and ileal arteries that form arcades and vasa recta to nourish the loops of the small intestine. The proximal part of the duodenum gets blood from foregut vessels (celiac trunk via the gastroduodenal and superior pancreaticoduodenal arteries), while the distal duodenum and the rest of the small intestine rely on the SMA. The renal arteries supply the kidneys, and the inferior mesenteric artery supplies the hindgut. So the artery that supplies the small intestine is the superior mesenteric artery.