Fig. 9
From: Lymphatic vessel: Origin, heterogeneity, biological functions and therapeutic targets
Lymph absorption and transport. a Capillary lymphatics comprise a single layer of loosely connected LECs lacking a continuous basement membrane and perivascular mural cells. LECs within capillary lymphatics are interconnected through discontinuous button-like junctions that facilitate the uptake of interstitial fluid, macromolecules and immune cells which are released by the blood capillary; b Collecting lymphatics have a period of brisk contraction (systole) and a period of relaxation (diastole) between each phasic contraction. Each lymphangion, defined as the segment between two valves, can typically exhibit systole and diastole. When a lymphangion is relaxed, the inflow (or upstream) valve will open (given sufficient inflow pressure). During systole, the phasic contraction pushes the lymph, but the inflow valve closes, so that lymph is forced forward through the outflow valve. LECs lymphatic endothelial cells. Created with Adobe Illustrator
