Why do lymphatic capillaries have valves in them?

Valves in veins are one way valves in the tunica intima(endothelium) of the drainage vessel. They allow the blood to defy gravity and continue circulating up towards the heart to dump into the inferior/superior vena cava. They ensure that blood travels the direction it is supposed to, and does not fall back the wrong way. Lymphatic capillaries are part of the capillary exchange that occurs from artery->artierole->CAPILLARY DIFFUSION->venule->vein->heart. they are an accessory drainage system, beginning blindly in the body and eventually meeting up with the vein again.