structure that prevents backflow of fluid in lymphatic vessels
Lymphatic vessel The lymphatic circulation begins with blind ending (closed at one end) highly permeable superficial lymph capillaries, formed by endothelial cells with button-like junctions between them that allow fluid to pass through them when the interstitial pressure is sufficiently high.[3] These button-like junctions consist of protein filaments like platelet endothelial cell adhesion molecule-1, or PECAM-1. A valve system in place here prevents the absorbed lymph from leaking back into the ISF. There is another system of semilunar (semi=half; lunar=related to the Moon) valves that prevents back-flow of lymph along the lumen of the vessel.[3] Lymph capillaries have many interconnections (anastomoses) between them and form a very fine network.[4]