If these toxins are not removed, they can build up in the blood and eventually poison us. Bone marrow Bone marrow is the soft tissue in the center of all the bones in the body. It produces both red and white blood cells. These two types of white blood cells are the immune system's front-line fighters. The bone marrow also houses the lymphocytes known as B cells until they reach maturity.
B cells fight disease by secreting antibodies into the body fluid.
These antibodies fight bacteria and viruses. The thymus is located near the top of the lungs and behind the breast bone. It is a key to immune response. Lymphocytes known as T cells get their name from the thymus because after the bone marrow produces them they are passed on to the thymus, which fosters their development. T cells both regulate immune response and attack infected or malignant body cells.