ULTRASTRUCTURAL FEATURES OF THE DIGESTIVE SYSTEM OF THE ADULT HELMINTH Heterakis gallinarum SCHRANK, 1788 (NEMATODA: HETERAKIDAE)

Abstract

Species of the Heterakidae family are similar in appearance. These signs cause difficulties in determining the systematic position of the species. For this purpose, the digestive organs of adult H. gallinarum nematode were studied at the ultrastructural levels by light and electron microscopic methods. The obtained results were compared with the structures of other species of the family. The digestive organs of adult H. gallinarum nematode are divided into 3 parts - stomodeum, intestine and proctodeum. The esophagus in turn is divided into procorpus, metacorpus and bulb. Its wall consists of basement membrane, muscle cells and cuticle. In the bulb, the muscle cells are large and relatively large in number. The intestine is divided into ventricular, middle and prerectal areas. It consists of a thick basement membrane, a single-layered epithelium with microvillas. Epithelial cells are divided into 5 areas that differ from each other according to their structure. The smooth membranes of the epithelial cells create a barrier connection with each other. Sphincter cells are noted at the end of the intestine. After that part, the rectum was found in females and the cloaca in males nematodes. The lumen of both is covered with cuticle. The ultrastructural features of the digestive organs of the nematode H. gallinarum are consistent with the main systematic features of the family.