Immunity Flashcards
(20 cards)
What is active immunity
It is produced by stimulating the production of antibodies by the individuals own immune system. Direct contact with the pathogen or its antigen is necessary
What is natural active immunity
Results from the individual becoming infected with a disease under normal circumstances. The body produces its own antibodies and may continue to do so for many years
What is artificial active immunity
Forms the basis of vaccination, involved inducing an immune response in an individual without the symptoms of the disease through use of a vaccination
What is passive immunity
Produced by the introduction of antibodies from an outside source. No direct contact with pathogen or antibody required to induce immunity which is acquired immediately
Not being produced by person so aren’t reproduced when broken down
No lasting immunity
What are pathogens
Microorganisms that can cause disease
Damage cells/tissues
Produce toxins
what is herd immunity
sufficiently large proportions of the population has been vaccinated to make it difficult for a pathogen to spread within a population
describe the primary and secondary immune response in relation to vaccines
before vaccination no antibody released because patients not yet encountered the antigen in the vaccine
primary response after first dose, activates the expansion of B cells into plasma cells which can then release antibodies
secondary dose - second response produce antibodies quickly
how do vaccines work
contain antigen injected into person
antigen on pathogens surface bind to receptor on helper t cell
t cells release cytokines
stimulates b cells to divide by mitosis and make clones
plasma cells from b cells make antibodies
some b cells become memory cells
on second exposure the memory cells produce antibodies rapidly
structure of a virus
lipid envelope matrix attachment proteins capsid protein layer two single strands of rna and enzymes reverse transcriptase
what does it mean by antigenic variability in relation to a virus
changes antigens frequently therefore it is hard to develop a vaccine present in HIV
how does a virus replicate
HIV binds to the CD4 on T helper cells
protein capsid fuses with the cell membrane of t cell
RNA turned to DNA using reverse transcriptase
DNA inserted into t cells genetic material
mRNA created
mRNA can leave nucleus and use host cells machinery to make HIV particles
what can monoclonal antibodies be used in
pregnancy tests
medication cancer cells
medical diagnosis PSA/mumps
all variations of ELISA
what are the ethical issues with using monoclonal antibodies
production of monoclonal antibodies mice are used to produce both antibodies and cancer cells. some trials with mab have been useful in cancer and diabetes
what are the two types of lymphocytes
t cells mature in the thymus and are associated with cell mediated immunity
b cells mature in bone marrow and are associated with antibodies/ humoral immunity
memory cells carry immunological memory of a specific antigen plasma cells produce antibodies
describe the process of cell mediated immunity
pathogen contains antigen on the surface of the cell
pathogen taken up by phagocyte and antigen presented on the surface of phagocyte
binds with receptor on the specific T helper cell
T helper releases cytokines and activates other t cells
divides to form clones by mitosis
cloned t cells stimulate phagocytes to engulf pathogens by phagocytosis. stimulate b cells to divide into memory cells and plasma cells by mitosis . stimulate cytotoxic t cells to divide and kill the bacteria
what is agglutination
clumps of bacterial cells are formed making it easier for the phagocyte to engulf them
describe an antibody
protein that is a specific/ complementary shape to the antigen. theyre produced by b cells and secreted by plasma cells. specific due to tertiary structure. destroy pathogen. made in body after infection. made of 4 polypeptide chains. complementary to only one antigen. constant region binds to receptors on B cells
whats a marker
stimulates phagocytes to engulf the bacteria cells to which the antibodies are attached
whats the humoral response
b cells can be antigen presenting cells or can bind to the antigen or can be presented by phagocytes
once the b cell has processed the antigen or bound to it its activated by helper t cells
b cells divide by mitosis to form a clone or identical b cells. b cells also divide into plasma cells which release antibodies
some b cells develop into memory cells they can respond to future infection dividing rapidly and developing into plasma cells that produce specific antibodies
whats an antigen
what are monoclonal antibodies
foreign protein on the cell surface that stimulates an immune response
made from a single clone of b cells used in pregnancy tests
