Adaptive Immunity
Adaptive immunity includes B and T cells. B cells are a type of white blood cell called a lymphocyte. Lymphocytes start out in the bone marrow and either stay there, maturing into B cells which produce antibodies necessary to fight off infections, or go to the thymus gland to mature into T cells. B lymphocytes are like the body’s military intelligence system — they find their targets and send defenses to lock onto them. T cells (or ‘killer cells) are like the soldiers, they destroy the invaders that the intelligence system finds.