The lymphatic system is made up of thin tubes that branch into all parts of the body. These vessels carry lymph, which is a colourless, watery fluid that contains a particular type of white blood cell called a lymphocyte.

Along this network of vessels are groups of small, bean-shaped organs called lymph nodes. Other organs associated with the lymph system are the spleen, the tonsils, and the thymus gland.

Functions of the Lymphatic System:

• Lymphocytes protect the body from microbes, foreign cells, infection and cancer cells.
• Lymphatic vessels drain tissue spaces that have fluid that escapes from blood capillaries.
• Lymphatic vessels transport fat from the gastrointestinal tract into the blood.

Components of the Lymphatic System

Lymphatic vessels, like blood capillaries, branch into all parts of the body. The vessels are permeable to white bloods cells and tissue fluid. The vessels circulate lymph, which is a watery fluid that contains lymphocytes.

The flow of lymph through the vessels results from pressure caused by movement of skeletal muscles and breathing. Lymph flows in one direction due to valves in the lymph vessels. The lymphatic vessels also drain fluid that escapes from blood capillaries.

Lymph nodes are small oval organs connected to the network of lymphatic vessels. Clusters of lymph nodes are found in the underarm, pelvis, neck, abdomen, and other sites.

The lymph nodes trap foreign substances, which are destroyed by lymphocytes. The lymph nodes also produce lymphocytes.

The Spleen is the largest lymphatic organ, and is located in the upper abdomen. The spleen creates lymphocytes and filters old and damaged cells from the blood.

Lymphocytes are a type of white blood cell made in the bone marrow and by other organs of the lymph system. Lymphocytes destroy foreign cells, microbes and cancer cells.