The document summarizes the lymphatic system. The lymphatic system consists of lymph, lymphatic vessels and ducts, and lymph nodes. It drains lymph fluid from tissues back into the bloodstream. Lymph is formed from interstitial fluid that leaks from blood capillaries but cannot reenter them. It is collected by lymphatic capillaries and vessels containing valves, and is transported to lymph nodes where it is filtered before draining into larger ducts and veins. The lymphatic system functions in drainage, defense against pathogens, and fat absorption from the intestines.