Gross anatomy of the intestine and their peritoneal folds in the chinchilla (Chinchilla lanigera)

ABSTRACT

The species belonging to the order Rodentia have great noticeable differences in their intestinal anatomy, particularly in the cecum and ascending colon. The anatomy of the intestines and its their mesenteries of Chinchilla lanigera have not been completely described. In the present study, ten adult Chinchilla lanigerawere studied using gross dissection. The small intestine was divided into duodenum, jejunum and ileum as usual. The duodenum started at the pylorus with a cranial portion, which dilated forming a duodenal ampulla. The ileum was very short and attached to the coiled cecum by means of the iliocecal fold. The ascending colon presented three parts. The first one, starting from the cecum and attached to it by the cecocolic fold presented sacculations on its external part. This could be named proximal loop (Ansa proximalis coli), having two parts, a proximal and distal one. The second part of the ascending colon was simple (Pars intermedia). The last part of the ascending colon (Ansa distalis coli) extended from the intermediate part to the right colic flexure. The distal ansa was formed by two parts parallel to each other and joined by an apical flexure and the ascending mesocolon. The descending duodenum was fixed to the pars intermedia of the ascending colon by a peritoneal fold named accessory duodenocolic fold. The ascending duodenum was fixed by the duodenocolic fold to the descending colon. This study indicates that there are minor differences in the divisions of the intestine and their peritoneal folds, as it usually happens when comparing other rodents.