[Xenarthras: intestinal topography and vascular relationships with serosa]

ABSTRACT Xenarthras (Mammalia, Dasypodidae) of the species Dasypus novemcinctus and Euphractus sexcinctus had their scientific anatomy studied in relation to the topography of the small and large intestines, their peritoneal relationships, external morphology and irrigation. Measurements of the different intestinal segments and the number of vessels destined for them were taken for comparative purposes. The method predicted: fixation (7% formaldehyde); latex injection; dissection and photo documentation. Spatially, the intestines, although fixed by a double peritoneal membrane, as in other vertebrates, in these, the serosa connected the duodenum, jejunum, ileum, and the colon in a single ligament fixed to the animal's back. Duodenum and pancreas, intraperitoneal, like the rectum, were fixed in the major and minor pelvis respectively and dorsally. Vessels derived from the mesenteric celiac trunk and the aorta traveled through the interior of the mesoduodenum, common mesentery, mesocolon and mesoride, being related to the lymph node chains along their pathways. The peritoneal rotation model, the external morphology as well as the model of intestinal vascularization were interpreted as basal, differing from recent vertebrates, according to literary support.