Abstract:
Recent studies have described the importance of snakes, in relation to their utility in several medicinal fields. However, gaps are common in the field of snake histology, which is part of the basic knowledge on these animals. Similarly, not enough information has been published on the digestive system of the grass snake (Natrix natrix). Natrix natrix was first described in 1758, by Linnaeus. It is sometimes called the ringed snake or water snake, and it belongs to Reptilia Class, Squamata Order, Serpentes Suborder, Colubridae Family, Natrix Genus. The grass snake is widely distributed in mainland Europe, northern Africa and the Middle East. It is considered one of the most common snakes in Romania. The gastric wall reveals four layers: mucosa, submucosa, muscular layer and serosa. The mucosa has projections to the lumen, similar to those of the mammals and is composed of a lining epithelium with non-ciliated simple columnar cells (cambered), lamina propria and gastric glands. Lamina propria is composed of richly vascularized connective tissue. Two categories of glands were observed: mucosal glands, located on top, made of mucosal cells, with flattened nuclei at basal pole and vacuolar cytoplasm; serous glands, located at the bottom, made of serous cells, with central spherical nuclei and intensely colored cytoplasm. The submucosa is well represented and richly vascularized. The muscle layer of the wall was composed of an inner circular, and an outer longitudinal layer. the maximum thickness is associated with the posterior area. The serosa is composed of richly vascularized and innervated connective tissue.
