U4A1: 7A DETECTING PATHOGENS Flashcards
define pathogen
an agent that causes disease
define antigen
molecule that may trigger an immune response
define self-antigen
mark the cells of an organism as ‘self’ so that the immune system doesn’t attack them.
2 classes of self-antigens
MHC 1, on all nucleated body cells
MHC 2, on specialised immune system cells
define non-self antigen
antigens the immune system reads as ‘foreign’. the immune system activates and destroys.
2 common antigen malfunctions
autoimmune disease, where the immune system recognises self cells as non-self cells
allergies, where the immune system overreacts to allergens (harmless non-self antigen)
how do red blood cells label themself as ‘self’ cells?
they don’t have MHC proteins, instead they use different glycoproteins to distinguish between blood types.
define cellular pathogens
have a cellular structure and are living organisms
4 types of cellular pathogens
bacteria
fungi
worms
protozoas
examples of bacteria
meningitis, tetanus
examples of fungi
thrush, tinea
examples of worms
tapeworm, roundworm
examples of protozoas
malaria
define non-cellular pathogens
do not have a cellular structure and are non-living.
2 types of non-cellular pathogens
viruses
prions
