NORMAL STRUCTURE, FUNCTION AND HISTOLOGICAL FEATURES OF THE THYMUS

The thymus is a primary lymphoid organ and, in immunological terms, serves as the
source for the development of T-lymphocytes. It is also characterized by morphological
diversity in its structure. Undoubtedly, the thymus is an epithelial organ in which
epithelioreticulocytes form specialized structures that ensure the development and
maturation of T-cells, along with other cells of the lymphoid lineage. The presence of
symbiotic interactions between the thymic microenvironment and developing
thymocytes has been established. It is also recognized that T-lymphocytes matured
under thymic control subsequently enter the systemic circulation. The cortical substance
of the thymus is densely populated with thymocytes, against which
epithelioreticulocytes are relatively sparse. In the medullary substance of the thymus,
more mature cells are located, while epithelioreticulocytes and other cell types are
represented more abundantly. Understanding the normal morphological characteristics
of the thymus, as well as the changes that occur under the influence of environmental
factors, is of key and decisive importance for assessing the systemic immune function
of the organism.