MORPHO-FUNCTIONAL ORGANIZATION OF THE MEMBRANOUS PORTION OF THE TRACHEA IN DOGS OF DECORATIVE BREEDS

Objective - to study the histological organization of the membranous part of the trachea in dogs of decorative breeds. Materials and methods. Membranous part of the trachea was studied on 15 tracheal samples obtained from intact dogs of the Yorkshire Terrier and Spitz breeds, which died from the diseases not associated with the pathology of the respiratory system. Fivemicrometer-thick paraffin sections were stained with hematoxylin-eosin and with Van Gieson. Results. It was found that normally in dogs of decorative breeds the membranous portion of the trachea consisted of three tunics: mucosa, fibro-muscular tunic and adventitia. Mucosal epithelium was represented by simple pseudostratified cuboidal epithelium with a weakly developed ciliary apparatus and single goblet cells. The middle tunic consisted of the interwoven circular bands of smooth muscle cells which were bound together with dense fibrous connective tissue made mainly of collagen and a small number of elastic fibers. Conclusions. The mucous membrane of the membranous part of the trachea does not participate in the conditioning of the incoming air. The damage of elastic scaffold of the middle tunic may result in its disorganization and become a prerequisite for the development of the tracheal collapse.

trachea, collapse, dog, membranous trachea