Immune system cells Flashcards
what are pluripotent haematopoietic stem cells
undifferentiated cells that can become a variety of blood cells
what can pluripotent haematopoietic stem cells initially differentiate into
myeloid stem cells lymphoid stem cells dendritic stem cells
what can myeloid stem cells become
megakaryocytes reticulocytes promyelocytes
what is the role of megakaryocytes
produce platelets
what do reticulocytes become
RBCs
what do promyelocytes become
macrophagesneutrophils eosinophils mast cells basophils
where do lymphoid stem cells travel to
thymus to differentiate into T and B lymphocytes
where to B cells mature
bone marrow
what do B cells differentiate into
plasma cells memory B cells
where do T cells mature
thymus
what do t cells differentiate into
CD4 cells - helper cells CD8 cells - cytotoxic cells natural killer cells
what are reticulocytes
immature RBCS released from bone marrow
when do reticulocytes becomes RBCs
when they lose their reticulum
features of macrophages
monocytes kill pathogens and abnormal cells by phagocytosis release cytokines to initiate inflammatory response
role of neutrophils
circulate in blood migrate to areas of inflammation kill pathogens by phagocytosis
role of eosinophils
contain granules with proinflammatory cytokines and toxic chemicals respond to parasites exocytose the granules, phagocytosis
what are mast cells
cells that are fixed in place in tissues contain cytoplasmic granules degranulation releases pro-inflammatory cytokines
structure of B lymphocytes
cell surface is lined with antibodies each B cell has a specific type of antibody for a specific antigen B cells only recognise antigens that match their antibodies
what can B cells become when activated
plasma cells - secrete antibodies aka immunoglobulins memory B cells - part of adaptive immune system
T cell structure
cell surface lined with T cell receptors each T cell has a specific receptor for a specific antigen
what do CD4 T cells become when activated
T-helper cells help other cells become activated
what do CD8 cells become when activated
cytotoxic T cells
function of cytotoxic T cells
granule exocytosis to destroy cells activate Fas pathway to cause apoptosis
function of NK cells
activated by cytokines from macrophages and interferons recognise infected or abnormal cells destroy cells release IFN-Y to activate macrophages
function of dendritic cells
take up antigens to process and display on cell surface take the antigens to lymph nodes to activate T cells
