Anatomical study of the abdominal arterial system in soricids (Insectivora, Mammalia): functional and phylogenetic...

Information on the anatomy of the abdominal arterial system in Insectivora is scarce. We described the origin, distribution, and variations of the visceral abdominal arteries in some Soricidae in order to provide the first comprehensive data on this subject in Insectivora. Results were interpreted from a functional and phylogenetic viewpoint.

The sample examined consisted of 46 shrews (25 Crocidura russula, 12 Sorex araneus, 5 S. coronatus, 4 S. minutus) captured in the field. Animals were analyzed by injection of coloured latex solution through the left ventricle of the heart and subsequent dissection.

The coeliacomesenteric trunk was the first visceral branch of the abdominal aorta. The cranial mesenteric artery supplied those parts of the digestive tract attached to the cranial mesentery and usually gave rise to the colic, the caudal pancreaticoduodenal, and the jejunum-ileumcolic arteries. The coeliac artery mainly vascularized the stomach, the liver and the first portion of the duodenum, and the spleen by means of several branches of the left gastric, the "common" hepatic, and the lienal arteries, respectively. The lienal arteries were double. The renal, gonadal, and median sacral arteries were also branches of the abdominal aorta. The caudal mesenteric artery emerged either from the abdominal aorta or from one of the common iliac arteries.

Differences in the abdominal blood supply between soricids and more advanced mammals are basically focused on the irrigation of the digestive tract. The presence of double lienal arteries and the absence of right gastric artery and left and right gastroepiploic arteries are related to the primitive type of gut presented in the order and are thought to be the plesiomorphic condition in Eutheria.