Morphological Features of the Digestive Tube in Sand Lizards, Lacerta agilis (Sauria, Lacertidae)

Abstract

The features of the sand lizard (Lacerta agilis) digestive tube morphology are presented in the article. It has been found that the sand lizard gastrointestinal tract includes oral cavity, esophagus, stomach, small intestine, large intestine and cloaca. The mucous membrane of the oral cavity is lined with non-keratinized stratified squamous epithelium. The esophagus is represented by an extensible canal; the distinction between the esophagus and the stomach is not expressed. The availability of a large number of ventricular fossae have stipulated a large area of the gastric mucosa and its cellular structure. The stomach is separated from the duodenum by a well-developed annular fold (pylorus). Villi of the duodenal mucosa are narrow, of different heights, covered with a single layer of columnar epithelium. The jejunum villi are of a more elongated shape, with more goblet cells and fewer crypts, the ileum villi are short. Small clumps of lymphoid cells are observed in the mucous membrane of the small intestine. The mucous membrane of the large intestine is lined with ordinary columnar epithelium containing goblet cells. Lymphoid aggregates are found in the wall of the large intestine. The cecum, as a distinct morphological section of the large intestine, is not presented.