ABSTRACT
The intestines are supplied by a series of parallel circulations from branches of the superior and inferior mesenteric arteries. There are extensive anastomoses between these vessels, but blockage of a large intestinal artery still leads to infarction of the bowel. The blood flow to the mucosa is greater than that to the rest of the intestinal wall, and it responds to changes in metabolic activity. Thus, blood flow to the small intestine doubles after a meal, and the increase lasts up to 3 hours. The intestinal circulation is capable of extensive autoregulation, i.e. it is independent of systemic blood pressure.
