Current knowledge on the functional morphology of the human spleen

The knowledge on the functional structure of the spleen is gained from the analysis of diseases, and immunological studies. Significant information is gained from model tests and isolated cells. The latter is advantageous in coincidence with the studies of intercellular relations. The main function of the spleen resides in "purification" of the blood. The vascular system, white pulp, red pulp and the marginal zone participate in this process. T-dependent zones of the white pulp are restricted by the circumference reticulum (CR) of periarterial lymphatic sheaths. CR is a morphologic substrate of retro-directional flow of lymphocytes. In addition to T lymphocytes and a certain amount of B lymphocytes, the T-dependent zones contain interdigitizing cells. The B-dependent zones, in addition to lymphocytes, contain dendrite reticular cells. The cords are constituted by varied cellular and extracellular compartments, especially macrophages, fibroblastic reticular cells and various fibrous components. The latest filtration barrier is formed by the wall of sinuses of the red pulp. The achievement of new functional knowledge resides prospectively in the use of lectins, anti-collagen antibodies, fibronectins, proteoglycanes and other various molecules participating in intercellular relations, or morphometric studies, they can provide information on the newest subpopulations of cells in both red and white pulp, that are so far inaccurately defined.