defence and immunity Flashcards
what is immunity?
the ability to fight an infection before showing symptoms
what is a lymphocyte?
a type of specific defence white blood cell (T or B cells)
what is a pathogen?
a microorganism which causes disruption to the body’s normal processes required to be healthy
what is direct damage?
destruction caused by pathogens directly destroying cells, eg ripping the membrane
what is indirect damage?
destruction caused by waste products (toxins) from pathogens
what is non-specific defence?
defence which is faster and doesn’t recognise individual pathogens (physical barriers, phagocytosis)
what is specific defence?
defence which is longer lasting and slower acting (lymphocytes)
what is the role of glycoproteins in immunity?
they act as receptors on our cell membranes to signpost them as “self”
what are chemoattractants?
toxins or chemicals released by pathogens which can be detected by phagocytes
what is a phagosome?
a vesicle within a phagocyte containing an internalised pathogen
what is a phagolysosome?
a merged phagosome and lysosome which breaks down a pathogen
what is histamine?
a chemical produced by the body to cause inflammation and speed up delivery of phagocytes to the site of infection
why might a self cell be recognised as a pathogen?
if it is infected by a virus, cancerous or has left over antigens from phagocytosis
what is apoptosis?
cell suicide, when an infected cell displays viral antigens on its membrane
what complex is created when a pathogen and T cell collide?
an antigen-receptor complex
what can T cells differentiate into?
T helper (H), T killer (C), or T memory (M)
what is histamine?
a chemical produced by the body
