REGULARITIES OF THE FORMATION OF THE TOPOGRAPHY OF THE LYMPHOID SYSTEM OF THE THORACIC CAVITY IN THE INTERMEDIATE FETAL PERIOD OF HUMAN ONTOGENESIS

The aim of the study was to detect the regularities of the formation of the topography of the organs of the lymphoid system of the thoracic cavity during the intermediate fetal period of ontogenesis. 191 human fetuses at the age of 16-22 weeks were examined using the methods of macro-microscopic dissection of saw-cuts according to N. I. Pirogov, the production of histotopograms, the study of projection anatomy, and the description of quantitative topography. It was found that the topography of the thymus was characterized by a clear stable skeletotopy, an expansion of the holotopic boundaries from the sternal to the midclavicular lines and a dynamic syntopy that manifested itself in the relationship with the diaphragmatic nerves, left brachiocephalic vein, heart chambers and large vessels of the mediastinum. The parietal lymph nodes of the chest are located between the inner thoracic vessels, in the projection of the costal-vertebral joints and under the the sympathetic trunk ganglia. At weeks 16-22, the most intensive growth was observed in the lateral pericardial and upper tracheobronchial lymph nodes. All groups of lymph nodes were found to descend by 1-2 thoracic vertebrae by week 22.

thymus, lymph nodes, topography, thoracic cavity, human fetus