Immune System Flashcards
why is a good immune system so important?
pathogens are complex and ever changing - we can’t exclude them but can keep numbers down
how do we stop pathogens?
distinguish between self and non-self
innate immunity
adaptive immunity
what is adaptive immunity?
recognise traits of specific pathogens
whats the first line of defence and what makes it difficult?
defence/stop it getting in
eating, breathing, reproduction
how do physical features help?
mucus stops pathogens
saliva/tears damage pathogens
defences in invertebrates?
barriers
phagocytosis - innate cells to detect/destroy pathogens
antimicrobial peptides/proteins - disrupt cell membranes of some pathogens
defences in vertebrates?
barriers
phagocytosis
anitmicrobial peptides/proteins
interferons - proteins that inhibts viral replication
imflammation - local increase in dilation of blood vessels
natural killer cells - detect/inhibit replication of cancerous cells
what is fever?
inflammatory response - control does little to help
examples of innate immunity?
some cells get engulfed by host and then resist breakdown and hide from immune system
some bacteria have an outer capsule that interferes with molecular recognition
what is an antigen?
triggers a response
what is an epitope?
small protion of the antigen that binds to the antigen receptor
what are B lymphocytes?
bind to epitopes on intact antigens protuding from pathogens
what are T lymphocytes?
bind to fragments of antigens on surface of host cell
what is the histocompatibly complex?
protein with the antigen fragment
what do lymphocytes develop into?
effectors - short term, immediate effect
memory - long term, give rise to effectors in future if same pathogen encountered again
