Macrophages Macrophages are not measured because they are found in tissue, especially GI tract, lungs, skin, spleen . First cells to pick up foreign organisms that enter by routes other than blood . Essential for immune system to work. They process foreign material and present it to other cells. CD 4 cells produce IL-2 and other interleukins .
B lymphocytes respond to processed organisms.
They are transformed to plasma cells . Plasma cells Mature B-lymphocytes that produce antibodies. Stress, exercise, menstruation cause lymphocytosis . Natural Killer Cells Unique lymphocyte s with c ytotoxic ability . Involved in all types of defense .