Histological features of the elk’s digestive tract organs

The purpose of research is to study the histological features of some organs of the digestive tract of elk. The work was carried out in 2023 at the Department of Anatomy, Pathological Anatomy and Surgery of the Krasnoyarsk State Agrarian University. The organs of the elk's digestive tract were subjected to histological examination: the esophagus, rumen, reticulum, booklet, abomasum and duodenum. Sections 5-7 μm thick were stained with hematoxylin and eosin using the Mallory method, Congo red, and viewed under a light microscope. It was revealed that the wall of the digestive tract of the elk as a whole has a histological structure typical of ruminants and is built from layers: mucous membrane with submucosa, muscular and outer membrane, represented by adventitia (in the esophagus) or serous (in other parts of the digestive tract). The mucous membrane is lined with epithelium, which changes along the course of the digestive tube from multi-layered (esophagus, rumen, reticulum, booklet) to single-layered (abomasum, intestine). The multilayered epithelium of the mucous membrane in the esophagus has signs of keratinization, and in the rumen, reticulum and booklet, keratinization is expressed only at the tops of the papillae. The smooth muscle plate is detected in the folds of the mucous membrane of the esophagus, rumen, abomasum, as well as in the leaflets of the booklet and the ridges of the reticulum, but it is absent in the papillae of the rumen, the papillae of the leaflets of the booklet and the papillae of the ridges of the reticulum. Distinctive features of the elk digestive tract are the presence of lipocytes in the muscular plate of the mucous membrane and in the submucosa of the abomasum, where adipose tissue almost completely replaces loose connective tissue. In addition, the muscular lining of the esophagus, along its entire length, is built exclusively from striated muscle tissue.