Full Blood Supply to the Intestines Description
[Continued from above] . . . that connects with the spleen (called the lineal artery), the left gastric artery (a branch which supplies the stomach), and finally to the common hepatic artery; further on, this artery is called the right gastric artery.
The superior mesenteric artery provides oxygen-rich blood to the entire small intestine; it has branches which extend as far as the middle third or so of the transverse colon.
The inferior mesenteric artery provides the blood supply to the left third segment of the transverse colon and also supplies blood the sigmoid colon with blood. Near the lower part of the body, the rectal arteries provide blood to this section of the intestines. This boundary is important for surgeons to understand, since the blood supply from the arteries and the way the veins drain does change in this area. The endodermal portion of the colon gets its blood from the sigmoid artery; this branches off of the inferior mesenteric artery. In contrast, the ectodermal section of the colon receives its blood supply from the rectal arteries, which arise from the internal iliac artery.