The lymphatic system removes foreign material and cell debris from tissues, and returns tissue fluid to the venous system. It is comprised of lymph capillaries, vessels, lymph nodes, and lymphoid tissues including the spleen, thymus, and tonsils. Lymph fluid drains from tissues via capillaries and vessels to lymph nodes, which filter out bacteria and foreign material. The thoracic duct and right lymphatic duct drain lymph from most of the body and empty into large veins in the neck. Regional lymph nodes throughout the body drain specific structures and tissues.