Pathogens& immune response Flashcards
Primary defences
Prevent pathogens entering the body, non specific
diseases
something that alters the normal functioning of the cell
pathogen&types
an organism that causes a disease
plants animal and fungi
skin as a barrier to infection
physical barrier
produces antimicrobial fluid
mucous surfaces as a barrier to infection
genitals, ears, mouth, nose
mucous traps pathogens and contains antimicrobial enzymes
blood clotting as a barrier to infection
platelets prevent entry to pathogens
T lymphocytes- response
contain specific receptors that bind to antigens on APCs
each T lymphocyte binds to a different antigen
clonal selection
clonal expansion- each T lymphocyte divides to produce clones of itself which carry out different functions
T helper cells
produce interleukins to activate B lymphocytes and T killer cells
T killer cells
attach to and kill infected cells
T regulatory cells
suppress the immune response so other white blood cells don’t attack own body cells
B lymphocytes
covered with antibodies that attach to the antigens to form an antigen antibody complex
each B lymphocyte has a different shaped antibody to bind to complementary antigens
clonal selection activated by T helper cells
The activated B lymphocyte divides by mitosis to form plasma cells and memory cells
plasma cells
clones of B lymphocytes that secrete a lot of the antibody specific to the foreign antigen
how do anitbodies attack infection? (3ways)
neutralisation toxins
agglutinating pathogens
prevention of pathogen binding to human cells
agglutinating pathogens
each antibody can bind to two pathogens at once, the pathogens become clumped together and can be engulfed by phagocytes
neutralising toxins
anti toxins bund to the toxins produced by pathogens and neutralise them so they arent affecting human cells
