It includes a network of vessels that assists in circulating the body fluids. These vessels transport excess fluid away from the interstitial spaces and return it to the bloodstream. Lymphatic Capillaries Lymphatic Capillaries are microscopic, closed ended tubes. The extend into the spaces within most tissues, forming complex networks that parallel the networks of the blood capilaries. The walls of the lymphatic capillaries, like those of the blood capillaries, consists of a single layer of squamous epithelial cells.
Fluids enter the lmyphatic capillaries.
Once the fluid does this a lymph is formed. The Lymphatic Vessels prevent backflow of lymph. They have specialized organs called lymph nodes. These nodes are vital in the defense against invasion of microorganisms. When the osmotic pressure of the tissue rise, it interferes with the osmotic reabsorption of water by the blood capillaries.