Left colic a.

The left colic artery is a branch of the inferior mesenteric artery that runs to the left behind the peritoneum and in front of the psoas major muscle, and after a short, but variable, course divides into an ascending and a descending branch.

The ascending branch crosses in front of the left kidney and ends, between the two layers of the transverse mesocolon, by anastomosing with the middle colic artery; the descending branch anastomoses with the highest sigmoid artery.

From the arches formed by these anastomoses branches are distributed to the descending colon and the left part of the transverse colon.