The main function of the lymphatic system is to transport lymph, which is a clear fluid containing white blood cells, throughout the body. This function helps the body rid itself of toxins and fight diseases.
The lymphatic system helps keep bodies healthy. It is made up of lymph, lymph nodes and lymph vessels. The spleen, thymus and tonsils are all part of the lymphatic system.
Lymph is a clear fluid that is transported throughout the body in its own system of capillaries. Lymph is responsible for removing fluid from inter-cellular spaces throughout the body. This inter-cellular fluid may contain bacteria, toxins or waste. Unlike the circulatory system, the lymphatic system only moves in one direction throughout the body: towards the neck. Lymph travels through lymph nodes to filter out all the unwanted material it collects from the cells. Each human body contains 600 to 700 lymph nodes. When lymph has been filtered through the nodes, it returns to the blood stream.
Lymph also contains white blood cells, most of which are made in the organs of the lymphatic system. If the lymph contains bacteria, the white cells create antibodies to fight off the bacteria. This is why lymph nodes swell when a human has a bacterial infection, such as strep throat.