A 70-year-old man has a 90% blockage at the origin of the

inferior mesenteric artery. He does not have intestinal angina.

Which of the following arteries is the most likely additional

source of blood to the descending colon?

(A) Left gastroepiploic

(B) Middle colic

(C) Sigmoid

(D) Splenic

(E) Superior rectal

The middle colic artery can supply the descending colon in case the inferior mesenteric artery is blocked.

Explanation:

In the intestines, the inferior mesentery artery supplies one-third portion of the transverse, descending and sigmoid colon on the left side.

The superior mesentery artery is divided into many branches like the middle colic artery. The middle colic artery after supplying the transverse colon divides into the left and right branches.

The left branch of the middle colic artery anastomoses (of the SMA) with the left colic artery (of the IMA) and supplies the descending colon. Hence, in case the origin of the IMA is blocked, the middle colic artery of the SMA can still supply to the descending colon.

Moreover, the patient does not have intestinal angina which usually occurs when the SMA is blocked. Since the SMA is not blocked, its branch middle colic artery can supply the descending colon.

The left gastroepiploic and splenic artery supplies the spleen, superior rectal artery supplies the rectal region.

Option B

Middle colic arteries is the most likely additional source of blood to the descending colon

Explanation:

The middle colic artery is a section of the superior mesenteric artery. Middle Colic provides the transverse colon, has a branch that runs to the right colon and branch that persists to the left colon that catches up with the left colic artery and proceeds as the marginal artery to provide the descending colon.

The left gastroepiploic artery is one of the sections of the splenic artery. Sigmoid - branch off IMA so barred in this case Splenic - proceeds of the celiac trunk, branches accumulation spleen & pancreas Superior Rectal - a sequence of IMA not possible to participate in this case