The lymphatic drainage from the skin is divided into six large tributary areas, which in turn consist of several territories that are connected to each other only by the cutaneous network of initial lymphatic vessels. The lymphatic vessels return the interstitial fluid to the venous system. The initial lymphatic vessels, arranged in a two- or three-dimensional network, absorb the interstitial fluid; the lymph is actively transported centrally by precollectors and further on collectors. Several lymph node stations are built into the course of the lymphatic vessels. In addition to their immunological function, these lymph nodes also have the task of setting a “colloid osmotic equilibrium pressure” of 60% of the plasma on average; this usually means a concentration, i.e., a fluid uptake from the lymph, for the peripheral lymph from the skin and subcutis.