Modern concepts of thymus morphology

The latest scientific data of the development, structure and cellular composition of thymus are studied and presented. Both widely known sources and new literature were used. This article is reporting external features of the structure of the thymus, internal structure, cellular composition. In particular, attention is paid to the description of the thymus zones, because there has been no consensus among morphologists in this matter. Embryonic development is described, as well as morphometric parameters in different periods of prenatal development. This article will be useful in writing scientific and certificating work, books and dissertation dealing the development of thymus, because there is more actually information about this theme.