[Historical notes on the lymphatic vascular system].

Abstract

The history of the progress in the knowledge of the lymphatic system can be divided in three main periods. The first one spans Egyptian. Greek and Roman civilizations until III century after Christ: the earliest topographical reports on collectors, major trunks and regional groups of lymph nodes date back to this age. The second period begins with Renaissance and extends until the end of XIX century. The scientific knowledge is no longer accepted as a collection of "unquestionable truths" but rather new discoveries are confirmed by painstaking descriptions and detailed pictures. We owe to Aselli (1622) the scientific description of lacteals. The new techniques of maceration (Malpighi, 1628) and of injection of different substances (water, air, mercury, cinnabar) allowed a strict check of the acquired knowledge and an accurate description of the superficial and deep lymphatic networks in different organs (kidney, heart). The documentation of the vascular lymphatic system culminates in the matchless work "Vasorum Lymphaticorum Corporis Humani..." by Paolo Mascagni (1755-1815) which Susini (1773-1814) immortalized in ceroplastic statues. The third phase covers the XX century. The studies deepen with the demonstration of lymphatic capillaries, endothelial cells. Macro- and microtopographical relationships between lymphatic and blood networks are described in detail and lymphatic vessels are studied at microscopic level. In the last decades ultrastructural and immunocytochemical researches develop in order to investigate the processes involved in lymph genesis and transendothelial transport of fluids, macromolecules and cells.