Photograph of the posterior abdominal wall showing the aorta and inferior mesenteric artery as well as its branches (a). The insert is shown in (b). Inferior mesenteric artery (IMA) gave off a left colic artery (LCA) which gave off a transverse branch to the descending colon and proceeded to give three sigmoid arteries (S1, S2, S3) it then proceeds to give a rectosigmoid branch (RCTSGM) and superior rectal artery (SRA).