disease and the immune system Flashcards
what is an antigen
a molecule that triggers an immune response when detected by the body
what is a phagocyte
a type of white blood cell
whats a lyzozome
enzymes that come from lysosomes
what type of cell is a t cell
white blood cell
what do t cells have on their surface and why
receptor proteins that bind to complementary antigens presented by phagocytes
what do T helper cells do
release chemical signals to activate and stimulate phagocytes and cytotoxic t cells
what to cytotoxic T cells do
kill abnormal and foreign cells
what type of cells are B cells
white blood cells
what are B cells covered with
antibodies
what is clonal selection
after antibodies bind to antigens substances from helper t cells activate B cells
what do activated B cells divide into
plasma cells
what do plasma cells secrete
monoclonal antibodies
the specificity of an antibody depends on what
its variable regions which form the antigen binding sights
what is the cellular immune response made up of
t cells and other immune system cells they interact with
whats the humoral immune response made up of
B cells, clonal selection and production of monoclonal antibodies
what is the primary immune response like- why
slow and weak - there arent many b cells to bind with
what gets left over after the primary immune response
memory cells
what is the secondary immune response like
quick and strong
why is the secondary immune response faster
memory B cells can divide into plasma cells fast and memory t can divide fast enough to kill cell carrying antigen
what do vaccines contain
antigens that cause your body to produce memory cells against a particular pathogen
describe what herd immunity means
vaccines protect individuals who have had them and reduce occurance of disease
how can vaccines be taken
injected or oral
whats a disadvantage of taking vaccines orally
they can be broken down by enzymes
antigens on the surface of pathogens activate what kind of response
primary immune response
when does antigenic variation occur
when a pathogen changes their surface antigen
what can antigenic variation be difficult for
vaccinations
what is active immunity
when your immune system makes its own antibodies after being stimulated by an antigen
what is natural active immunity
when u become immune after catching a disease