The lymphatic system consists of lymph, lymphatic vessels, lymphoid organs and lymphatic tissue distributed throughout the body. It has three main functions: returning tissue fluid to the blood, absorbing fats and fat-soluble vitamins, and helping the body defend against disease. The lymphatic system contains lymph nodes, tonsils, thymus gland, and spleen. Lymph is a fluid similar to plasma that is formed from tissue fluid and drained through lymphatic vessels into the bloodstream.