Understanding the lymphatic system

The lymphatic system is made up of a network of small vessels (similar to blood vessels), groups of lymph glands (nodes) that extend throughout the body (which the vessels are connected to), and other lymphatic tissue such as the tonsils, liver and spleen.

The lymphatic vessels transport a colourless fluid called lymph, which is made up of water, protein and other substances. It also contains white blood cells called lymphocytes that help your body fight infection.

Lymphatic fluid flows very slowly and continuously through the lymph vessels to clusters of lymph nodes, where it is filtered. Once it has passed through the lymph nodes, the fluid then finally drains back into the large veins of the body at a point just behind the collar bone, on each side of the neck. From there, it travels back to the heart and is eventually removed from the body via the kidney as urine.

The lymphatic system works with the blood system to maintain and protect the balance of fluid in the surface tissue of the body by draining, filtering and transporting lymphatic fluid around the body.