The arterial blood supply of the large intestine mainly comes from the superior and inferior mesenteric arteries.

The cecum, vermiform appendix, ascending colon, and proximal two-thirds of the transverse colon (the midgut derivatives) are supplied by the following branches of the superior mesenteric artery:

Cecum - supplied by the ileocolic artery;
Vermiform appendix - receives arterial blood from the ileocolic artery and its appendicular artery;
Ascending colon - supplied by the ileocolic and right colic arteries;
Proximal two-thirds of the transverse colon - receives arterial blood from the right colic and middle colic artery.

The distal third of the transverse colon, descending colon and sigmoid colon (the hindgut derivatives) are supplied by the branches of the inferior mesenteric artery:

Distal third of transverse colon - receives arterial blood from the left colic artery;
Descending colon - supplied by the left colic artery;
Sigmoid colon - supplied by the sigmoid arteries.

Note: During the embryological period, the gastrointestinal tract organs are derived from the primitive gut tube, which is divided into three portions: foregut, midgut and hindgut. Each of the portions is distinct in its embryological development and neurovascular supply. The foregut later develops into the esophagus, stomach, liver, gallbladder, pancreas, and the first part of the duodenum. The midgut develops into the rest of the duodenum, small intestine, and large intestine up to the proximal two-thirds of the transverse colon. And finally, the hindgut is the derivative of the remaining part of the large intestine up to the upper anal canal.

Anastomotic network

The superior and inferior mesenteric arteries communicate with each other via several anastomoses. One of them is formed between the middle colic artery and the left colic artery. However, it can also be created directly between the proximal superior mesenteric artery and the proximal inferior mesenteric artery. It is an inconstant anastomosis called the arc of Riolan or the central anastomotic mesenteric artery.

Also, all arteries of the large intestine form a unified anastomotic vessel called the marginal artery (also known as the marginal artery of Drummond). It runs parallel along the length of the large intestine from the ileocecal to the rectosigmoid junction. Since the main arteries forming the marginal artery are the branches of the superior mesenteric artery (ileocolic, right colic and middle colic arteries) and the inferior mesenteric artery (left colic artery), it is more pronounced along the cecum, ascending, transverse and descending colon. The sigmoid colon has a poorly developed marginal artery.

The marginal artery goes along the inner border of the large intestine, giving off numerous short branches that go towards the wall of the large intestine. These branches are called the straight arteries or vasa recta. The vasa recta can be further subdivided into the short vasa recta (short vessels) that run through the muscular layer and the long vasa recta (long vessels) that pass through the subserosa and muscular layer (muscularis externa), also supplying the epiploic appendices.

Surgical considerations:

Continuous blood supply facilitates resection and healing.
Caution needed at the left colic (splenic) flexure, where the anastomosis is between the middle colic and left colic arteries is weak.
This accounts for the high frequency of splenic flexure ischemia or infarction when the arterial supply is compromised by arteriosclerosis, embolism, or low blood flow seen in hypotension.
Surgeons must be aware of this weak anastomosis when removing sections of descending colon.

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Arterial blood supply of cecum and colon