immunity Flashcards
what is an antigen?
foreign protein that generates antibodies. It produces an immune response by stimulating T and B cells
what is an antibody
proteins that are specific to a particular antigen and are complimentary to it
what is a non specific immune response
response that is the same for all pathogens
what is a specific immune response
response that is specific to the antigen and it involves the stimulation of B cells (by T cells) and secretion of antibodies complimentary to antigen
what is a primary response
the multistep pathway from the antigen presenting cell to secretion of antibodies
what is secondary response
the stimulation of memory B cells to cause secretion of more antibodies more quickly than primary response
what is cell mediated response
done by T cells. They only bind to antigens on a HOST cell
what is humoural response
B cells and antibody secretion. antibodies are soluble proteins and therefore can enter tissue fluid and cause destruction of pathogen
Describe the process of the immune response
foreign antigen on a pathogen is detected and phagocyte then engulfs this by phagocytosis and phagocyte then presents antigen on its cell membrane
The antigen presenting cell then stimulates T helper cell by binding to it and the T helper cell contains a specific antigen receptor
This binding of T helper cell and antigen presenting cell stimulates the cloning of T helper cells by mitosis to make more T helper cells or cytotoxic t cells
these cytotoxic T cells kill infected host cell (APC) using perforin
B lymphocyte which contains specific antibodies are stimulated by binding to T helper cell
once B cell has been stimulated by binding to both antigen and specific T helper cell it differentiates into plasma cells which secrete specific antibodies or act as antitoxins or memory B cell which stays in blood and brings about immunity
