Anatomy of the Gastrointestinal Blood Supply

Anatomy of the Gastrointestinal Blood Supply

Figure 62–7 shows the general plan of the arterial blood supply to the gut, including the superior mesen-teric and inferior mesenteric arteries supplying the walls of the small and large intestines by way of an arching arterial system. Not shown in the figure is the celiac artery, which provides a similar blood supply to the stomach.

On entering the wall of the gut, the arteries branch and send smaller arteries circling in both directions around the gut, with the tips of these arteries meeting on the side of the gut wall opposite the mesenteric attachment. From the circling arteries, still much smaller arteries penetrate into the intestinal wall and spread (1) along the muscle bundles, (2) into the intes-tinal villi, and (3) into submucosal vessels beneath the epithelium to serve the secretory and absorptive func-tions of the gut.

Figure 62–8 shows the special organization of the blood flow through an intestinal villus, including a small arteriole and venule that interconnect with a system of multiple looping capillaries. The walls of the arterioles are highly muscular and are highly active in controlling villus blood flow.