Features of the macro and microscopic structure of the lungs of a mature rabbit – Oryctolagus cuniculus L. 1758

The macro- and microscopic structure of the lungs of mature rabbits – Oryctolagus cuniculus L., 1758 – European rabbit was studied. This work was performed using comprehensive research methods: anatomical, organometric, histological and histometric. The research was carried out in the conditions of the laboratory of pathomorphology in the Department of Anatomy and Histology. The scientific work was performed on the subject of research work of the Department of Anatomy and Histology of Polissya National University on the theme: “Development, morphology and histochemistry of animal organs in normal and pathological”, according to the state registration number – № 0113V000900. The morphological studies followed the basic rules of Good Laboratory Practice GLP (1981), the provisions of the “General Ethical Principles of Animal Experiments”, adopted by the First National Congress of Bioethics (Kyiv, 2001) and the requirements for the “Rules for carrying out work with experimental animals”, approved by the order of the Ministry of Health № 281 of November 1, 2000 “On measures to further improve the organizational forms of work with the use of experimental animals”. The material for histomorphological studies were pieces of lungs selected from clinically healthy adult rabbits (n = 5). Slices were made from paraffin blocks on a sled microtome MS–2. The thickness of histological sections did not exceed 8–12 μm, which were then stained with hematoxylin and eosin and Van Gizon to study the morphofunctional activity of cells and tissues of the respiratory tract. Histometric studies of histological specimens were performed using a microscope “Micros” with a digital camera at a magnification of × 100–1000. Studies have shown that macroscopically the lungs of mature rabbits have a reflection of the shape of the thoracic cavity, and gradually expands ventrally. The right and left lungs are surrounded by pleural right and left sacs. The pleural cavities of both lungs in the test animals are not interconnected. Organometry showed that the absolute lung mass of rabbits is 18.05 ± 1.32 g, relative to 0.624 ± 0.013 %. The histoarchitectonics of the lungs is formed by the lung lobes. The respiratory department of the lungs is represented by a set of acinuses. The latter are represented by respiratory bronchioles, alveolar passages, alveolar sacs and alveoli that form the alveolar tree. The results of morphometric studies showed that the respiratory (respiratory) part of the lungs of rabbits occupies 39.6 ± 0.62 %, and the connective tissue base, respectively, 58.5 ± 1.27 %. The average volume of alveoli, which are divided into small, medium and large, is 42.3 ± 4.35 thousand μm3. Thus, studies of the macro- and microscopic structure of the lungs of experimental animals are of great general biological importance, as they are an important criterion for objective assessment for the differential diagnosis of diseases of various origins.