Structural and Functional Characteristics of Different Histohematological Barriers of the Organism in Norm and during the Pathological Changes, their Medical Significance and Role in Forming Clinical Thinking of Junior Students

This review presents modern data on the structural and functional features of blood-brain, hematotesticular and hemato-ophthalmic barriers and pathologies that appear as a result of their dysfunction. The histohematic barrier is a specialized structure located between the blood and the tissue fluid regulating metabolic processes between them, ensuring the preservation of permanent physicochemical properties and composition of the tissue fluid. This barrier also prevents the penetration of harmful substances from the blood and supports an immune response of the organism. Normal functioning of different barriers of the body is due to their structure, environment, the level of their selective permeability and their regulation. Hystogematic barriers are directly related to the development of pathological processes, which means that they can become initial points of various diseases. Violation of permeability, neuro-humoral regulation, structural components and increased activity of enzyme systems that increase permeability can be the basis for developing different pathologies. According to the type of barrier there are pathologies of nervous and sensory systems, reproductive functions, immune processes, etc. New data on histohematic barrier are of great importance for the treatment of many autoimmune, neurodegenerative and other diseases. The knowledge of different barriers functioning in normal and pathological states allows not only to understand the cause of the disease, but also to pursue the search for methods of treatment. This knowledge enables doctors and pharmacists to create innovative and rational methods of correction and prevention of many pathological conditions, diagnosis of disorders associated with these structures in the early stages of the disease. The knowledge of histohematic barrier plays an important role in forming clinical thinking of junior students. Having acquired the necessary skills and abilities of histological analysis, junior students have the opportunity to comprehend the approaches to the diagnostic problems in solving future professional situations.