immunity Flashcards
what is innate immunity
non specific response which does not change based on the pathogen
what physical barriers is there to prevent pathogens
skin
mucus membranes
cillia
acid
lysosomes
what do chemical mediators do in the body
prevent cell entry
cause inflammation
stimulate adaptive immune response
how can the body discourage microbial growth
interferons
compliment system
iron binding proteins
anti-microbial proteins
how is an inflammatory response created
trauma causes pathogen to enter tissue
tissue damage causes release of chemical mediators like histamines and cytokines
these cause vasodilation, attracts phagocytes and lymphocytes and increases vascular permeability
why is an increase vascular permeability good
allows fibrinogen and complement to enter
fibrinogen blocks the area and stops spread of infection
what is a fever
systematic inflammatory response
how do natural killer cells cause destruction of infected host cells
release perforin which causes channels in the membrane, leading to cytolysis
granzymes induce apoptosis
what phagocytotic cells are involved in phagocytosis
neutrophils
macrophages
dendritic
eosinophils
NK cells
what is the role of neutrophils
first response and released the chemicals to increase inflamation
lysosomal activity
start to kill the cells
what is the role of macrophages
these wait in organs and will clean up after the neutrophils
what is the role of dendritic cells
found in organs in contact with environment and stimulate adaptive response
take antigens to B cells in the lymphatic system
what do eosinophils do
at mucosal surfaces and defend against multicellular things like parasites
what are the steps of phagocytosis
chemotaxis (detection)
adherence to the pathogen (helped by proteins)
ingestion (pseudopod surrounds the pathogen into phagosome)
digestion (phagolysosomes)
killing (microbes are degraded and anything left is kept in residual body)
how are non self cells recognised
antigens bind to antigen receptors on t or b cells
what is the part of an antigen which elicits and immune response called
the epitope
what are the two responses in the adaptive immune system
cell mediated (using t cells)
humoral (using b cells)
what roles does the lymphatic system have in the immune response
thymus - differentiation of t cells
lymph vessels transport phagocytes and lymphocytes
secondary lymphatic organs such as spleen and nodes home to lymphocytes and macrophages
where does clonal selection take place
secondary lymphatic organs
what are the classes of antibody
G M A D E
how are b cells activated
epitope of antigen detected
antibody is secreted
these act in the blood
how are b cells activated
epitope of antigen detected
antibody is secreted
these act in the blood
how do compliment proteins work
cause cells to rupture
how do compliment proteins work
cause cells to rupture
how do body cells present the antigen
antigen broken down into peptide fragments and bind to MHC-1 molecules
these are packaged into a vesicle and undergoes exocytosis and inserted into membrane
tells cytotoxic cells to kill the cell
how do class 2 cells present the antigen
they take up the antigen by endocytosis
use MHC 2 complex
attracts t helper cells
how do t cells recognise the antigen
recognises MHC molecules
requires interleukin 2 as costimulation which anchors the cell to the infected cell
what is different about a t cell antigen receptor
no hinge region
