The Lymph System
The word lymph comes from the Latin word “lympha” which means “water.” It was first described in the 17th century by Olaus Rudbeck and Thomas Bartholin. The lymph system is a network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials. It transports fluid, which contains your white blood cell army, throughout the body, and is an integral part of your immune system. It consists primarily of lymphatic vessels, which are similar to veins and capillaries, and lymph nodes, of which there are around 600 in the body. It also plays a role in absorbing fat-soluble nutrients. Your tonsils, adenoids, spleen, and thymus are all part of the lymphatic system.
Unlike blood, which flows throughout the entire body in a closed system loop, lymph flows in only one direction - upwards towards your heart and neck. The fluid gets moved along the vessel network by contractions of the lymphatic passages or by compression from external tissue forces (i.e., massage, physical exertion, etc.). It then empties into the two main lymphatic ducts, near your heart and neck. From there, the filtered fluid returns to the blood in the veins. As lymph vessels drain fluid from body tissues, foreign materials are examined by your immune cells. If you’ve ever had a swollen throat, for instance, your lymph nodes are swelling in response to infection, due to a build-up of lymph fluid, bacteria, and immune cells.