Development Lymphocyte

development of blood cells

mammalian stem cells differentiate several kinds of blood cell within bone marrow. process called haematopoiesis. lymphocytes originate, during process, common lymphoid progenitor before differentiating distinct lymphocyte types. differentiation of lymphocytes follows various pathways in hierarchical fashion in more plastic fashion. formation of lymphocytes known lymphopoiesis. b cells mature b lymphocytes in bursa equivalent, in humans galt, thought located in peyer s patches of intestine, while t cells migrate , mature in distinct organ, called thymus. following maturation, lymphocytes enter circulation , peripheral lymphoid organs (e.g. spleen , lymph nodes) survey invading pathogens and/or tumor cells.

the lymphocytes involved in adaptive immunity (i.e. b , t cells) differentiate further after exposure antigen; form effector , memory lymphocytes. effector lymphocytes function eliminate antigen, either releasing antibodies (in case of b cells), cytotoxic granules (cytotoxic t cells) or signaling other cells of immune system (helper t cells). memory t cells remain in peripheral tissues , circulation extended time ready respond same antigen upon future exposure; live weeks several years whole lifetime, long compared other leukocytes.