The lymphatic system is composed of a vast network of tubes (vessels) and grapelike clusters called lymph nodes. The vessels transport colorless fluid called lymph and cells of the immune system (lymphocytes) throughout the body. The lymphatic system resembles a river system. Small capillaries carry lymph into larger vessels which eventually drain into two large lymph vessels that empty into blood vessels at the base of the neck.(1)
The lymphatic system serves many purposes including: filtration, transport of fluid and initiation of immune responses. The vessels of the lymphatic system are responsible for absorbing and filtering the fluid which surrounds the cells and tissues of the body.(1)
Lymph nodes are small sac-like structures located along the lymph vessels. They are home to lymphocytes, a type of white blood cell.(1) Lymph nodes store lymphocytes and help control the immune response by allowing lymphocytes to come into contact with foreign materials (antigens) in a manner that stimulates their activity.(1)
All lymphocytes originate from stem cells in the bone marrow but they are not all the same.(1) The two main categories of lymphocytes are B cells and T cells. B cells fully develop in the bone marrow. T cells leave the bone marrow in an immature state and continue to develop in the thymus and other organs. T cells and B cells play different roles in the immune system and their functions are described more fully in the Vaccine section. (1)
The extensive nature of the lymphatic network allows it to serve as a way for cancer cells to spread throughout the body. Cancer metastasis frequently occurs via migration of cancer cells through the lymphatic system.(1) Learn more about metastasis
Learn more about lymphoma or make an appointment at the Winship Cancer Institute of Emory University.