Lymphatic Vessel Wall

The lymphatic vessel wall is the structural boundary of lymphatic vessels, responsible for transporting lymph throughout the body. Its composition varies depending on the type and size of the vessel, consisting of an endothelial layer (lymphatic endothelial cells expressing markers such as PECAM-1, PROX1, VEGFR-3, podoplanin, and LYVE-1), a discontinuous basement membrane in initial lymphatics, a smooth muscle layer in collecting vessels, and an adventitia. Valves prevent backflow, and anchoring filaments connect endothelial cells to the extracellular matrix. It allows uptake of interstitial fluid, transport of immune cells, and movement driven by intrinsic contraction. Dysfunction can lead to lymphedema or compromised immunity.