ANATOMO-HISTOLOGICAL STRUCTURE AND MORPHOMETRIC FEATURES OF THE CEREBELLUM OF DOMESTIC BIRDS

Abstract

An urgent issue that requires the attention of scientists – biologists, morphologists – is the study of the development, growth and formation of parameters of the structural features of organs and tissues, in particular, organs of the central and peripheral nervous system, which occupies a significant place in the regulation of all vital processes of living organisms. Special interest in the study of the organs of the nervous system is due to its various properties and functions: perception and conduction of nerve impulses, generation, transformation, storage of energy of various types and information of the external environment, ability of the nervous system to excite, inhibit, trophic function, etc. The connection of the cerebellum with the structural parts of the brain and the complex neural system of processing information coming to its cortex make it unique in terms of the variety of functions it performs. The cerebellum is not only the center of coordination of movements and balance, but also participates in the regulation of many other functions of the body. The article presents the results of studies of the anatomo-histological structure and morphometric features of the cerebellum of domestic birds belonging to the vertebrate subtype, class Aves – birds (Gallus gallus, forma domestica L., 1758 – domestic chicken, Meleaguis gallopavo forma domestica L., 1758 – turkey , Anas platyryncha forma domestica L., 1758 – domestic duck, Anser caerulescens forma domestica L., 1758 – goose). The morphological results complement and expand the information on the macro- and microscopic structure of the cerebellum in relation to the species characteristics of domestic ashes in the relevant sections of comparative anatomy, histology, forensic veterinary medicine, zoology, etc. According to the results of anatomical studies, the cerebellum in birds is located between the cerebrum and midbrain, dorsal to the medulla oblongata. The cerebellum is formed by the body and two right and left lateral ears. The surface of the organ is represented by numerous furrows, which are divided into lobes, the latter united into three lobes: front, middle and back. In the lateral projection, the cerebellum is triangular in shape, with a ventrally elongated apex. In the birds studied by us, the cerebellum is characterized by the general principles of its structural organization and morphotopography, but differs in its organometric indicators. According to organometry, the absolute mass of the cerebellum in poultry is different: the largest in turkeys is 1.987 ± 0.0086 g, the smallest in geese is 1.409 ± 0.0063 g, then in ducks is 0.932 ± 0.0041 and the smallest in chickens, which is 0.516 ± 0.0032 g. The relative mass of the cerebellum changes synchronously with the absolute mass and is 0.047 ± 0.0002% in turkeys, 0.041 ± 0.0002 in geese, 0.036 ± 0.0002 in ducks, 0.023 ± 0.0001% in chickens. The microscopic structure of the cerebellum of domestic birds has a similar structural organization: gray (cortex) and white matter are clearly differentiated on a cross section. The cerebellar cortex of birds is formed by corresponding layers (molecular, ganglionic, granular), of different thicknesses and is characterized by an unequal population of neurons, which have a determined relationship between the level of the morphofunctional state of nervous and innervated structures depending on the animal species.