The Immune System: specific immunity Flashcards
where are T cells produced
bone marrow as immature
where do T cells mature
thymus gland, under the influence of thymosin, becomes specialised
how do T cells become activated and what happens after
encounter infective connective tissue
travel around the bloodstream only attacking when they recognise the one specific antigen
where are B cells produced and matured
bone marrow
describe the function of B cells
produce antibodies/immunoglobulins, targets one specific antigen
define immunoglobulins
glycoproteins that bind and destroy antigens
describe T cells and the cell mediated response
encounter an antigen for the 1st time, they become sensitised to it
cannot detect free antigens in body fluids
so need antigen-presenting cells (APCs) to present the antigen
describe an APC
macrophage
engulf and digest antigen
presents antigen on plasma membrane
describe a cytotoxic T cell (CD8)
inactivate antigen carrying cells by releasing a toxin
destroy abnormal body cells
define abnormal in relation to the immune system
infected or cancerous
describe T helper (CD4)
produce cytokines (interleukins/interferons) to support and promote CD8 cells and macrophages
stimulate B cells to produce antibodies
describe T regulatory cells
turn off activated T and B cells
limiting the immune response’s potentially damaging effects
immunological tolerance
define immunological tolerance
preventing the development of autoimmunity and to protect the fetus during pregnancy
describe T memory cells
respond rapidly to followoing encounters with the same antigen
describe B cells and the antibody mediated (humoral) immunity
B cells recognise and bind to antigens directly
make antibodies, some released into the bloodstream for distribution but also B cells present antibody on plasma membrane
Helper T cells enable the B cells to enlarge and multiply making 2 B cells: Memory B cells
Plasma cells