The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the circulatory system and the immune system. It is made up of a large network of lymphatic vessels, lymphatic or lymphoid organs, and lymphoid tissues. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body. Lymphoid organs, The immune system is made up of organs that control the production and maturation of certain defense cells, the lymphocytes.,Bone marrow, Thymus, Lymph nodes, Spleen, Tonsils, Lymphatic tissue in the bowel and in other mucous membranes in the body. The lymphatic system is a system of thin tubes and lymph nodes that run throughout the body. Lymph is a clear-to-white fluid made of: White blood cells, especially lymphocytes, the cells that attack bacteria in the blood. Fluid from the intestines called chyle, which contains proteins and fats. The lymph is a biological fluid produced as the affluent of interstitial fluid from most parenchymal organs. The lymphatic system is a system of thin tubes and lymph nodes that run throughout the body.A number of specialised tissues are important for the proper functioning of the immune system. This phenomenon is applied to find sentinel lymph nodes in cancer patients. A significant fraction of the total immune cells in the body are located in several hundred lymph nodes.