The middle colic artery is a branch of the superior mesenteric artery that mostly supplies the transverse colon. It arises just below the pancreas, and, passing downward and forward between the layers of the transverse mesocolon, divides into two branches: right and left. The right branch anastomoses with the right colic artery The left branch anastomoses with the left colic artery, a branch of the inferior mesenteric artery. The arches thus formed are placed about two fingers' breadth from the transverse colon, to which they distribute branches. [WP,unvetted]. [ http://en.wikipedia.org/wiki/Middle_colic_artery ]