The blood supply in the large intestine of seven specimens of the lesser anteater, Tamandua tetradactyla, studied. The method included preparation of the macroscopic collection report, perfusion of the arterial network with water, injection of colored latex, fixation in formaldehyde, and preservation in ethanol. For our description and analyses, we performed dissections under mesoscopic light and made photo documentation of our observations. The large intestine of T. tetradactyla is irrigated by the caudal mesenteric artery (rectum, left colic fold, descending colon and transverse colon) and cranial mesenteric artery (right colic fold, cecal pouch). We observed that the large intestine in these animals is implied in the abdominal wall without becoming affixed to the wall, or developing adhesions on individual segments. The caudal mesenteric artery feeds the straight collateral branches (primary, secondary, and tertiary) and a few juxtacolic arched branches (first and second order). The straight branches emerge from the arched branches, bifurcate, and embrace the intestinal loop to irrigate it. The presence of anastomoses between the CaMA and the CrMA apparently ensures a relatively stable flow in the event of failure of either. This is very important, as the peritoneum in this species is completely dependent on blood from these two arteries. The model of vascularization and fixation of the large intestine into the abdominal wall of T. tetradactyla is different from that in other vertebrates.
Vol. 30 • No. 8
Vol. 30 • No. 8