Question 7

Outline the blood supply to the gastrointestinal system (arteries and veins).

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College Answer

An outline of the blood supply from the oesophagus down to the anus was expected. Very few candidates knew the branches of the main 3 arteries and which portion of the gastrointestinal system they supplied. Concepts related to control of blood flow and autoregulation of blood flow were not asked and therefore marks were not awarded for this information.


Major arterial structures and their branches:

  • Coeliac trunk
    • Left gastric artery
    • Common hepatic artery
    • Splenic artery
  • Superior mesenteric artery
    • Inferior pancreaticoduodenal artery
    • Intestinal (jejunal and ileal) arteries
    • Ileocolic artery
    • Right colic artery
    • Middle colic artery
  • Inferior mesenteric artery
    • Left colic artery
    • Sigmoid arteries
    • Superior rectal artery

The structures supplied by each branch are:

  • Coeliac trunk:
    • Abdominal part of the oesophagus
    • Stomach
    • Superior half of the duodenum
    • Liver
    • Superior half of the pancreas
    • Spleen
  • Superior mesenteric artery:
    • Intestine, from the lower half of the duodenum down to the splenic flexure of the large intestine
  • Inferior mesenteric artery:
    • Colon, from the splenic flexure down to the sigmoid and superior portion of the rectum

Major venous structures and their branches

  • Oesophagus is drained by branches of the azygous veins and the inferior thyroid vein
  • Mesenteric circulation drains via the superior and inferior mesenteric vein
    • These two vessels are then joined by the splenic vein
    • These form the portal vein
    • This then splits to form the right and left branches in the liver
    • From the portal vein, blood drains via the hepatic vein into the inferior vena cava
  • Lower third of the rectum and anus drain into the middle rectal vein, which drins directly into the IVC


Kornblith, Paul L., Scott J. Boley, and Brian S. Whitehouse. "Anatomy of the splanchnic circulation." Surgical Clinics of North America 72.1 (1992): 1-30.

Rosenblum, Jordan D., Catherine M. Boyle, and Lewis B. Schwartz. "The mesenteric circulation: anatomy and physiology." Surgical Clinics 77.2 (1997): 289-306.