lymphatic organ

A lymphatic organ is an organ that is characterized by clusters of lymphocytes and other cells, such as macrophages, enmeshed in a framework of short, branching connective tissue fibers. The lymphocytes originate in the red bone marrow with other types of blood cells and are carried in the blood from the bone marrow to the lymphatic organs. When the body is exposed to microorganisms and other foreign substances, the lymphocytes proliferate within the lymphatic organs and are sent in the blood to the site of the invasion. This is part of the immune response (see immune system) that attempts to destroy the invading agent. Lymphatic organs include:


  • lymph nodes
  • tonsils
  • spleen
  • thymus