lymphoid system

In vertebrates the lymphatic system is a network of conduits carrying a clear fluid called lymph, together with the lymphoid tissue through which that fluid travels. Lymphoid tissue occurs in many organs, particularly in the lymph nodes and in the lymphoid follicles associated with the digestive tract, such as the tonsils. The system is defined more broadly than its vessels alone: it also takes in all the structures dedicated to the circulation and production of lymphocytes, which brings the spleen, the thymus, the bone marrow, and the gut-associated lymphoid tissue within its scope. Classified as an anatomical system in its own right, it is recorded here under the Latin designation lymphatic circulatory system.