4.1.5 secondary non-specific defences Flashcards
antigen-presenting cell
cell that isolates the antigen from a pathogen & places it on the plasma membrane so it can be recognised by other cells in the immune system
clonal selection
selection of a specific B or T cell thats specific to the antigen
cytokines
hormone-like molecules used in cell signalling to stimulate the immune response
neutrophil
type of white blood cell that engulfs foreign matter & traps it in a large vacuole (phagosome) which fuses with lysosomes to digest the foreign matter
opsonins
proteins that bind me to the antigen on a pathogen & allow phagocytes to bind
what are secondary defences used for
combat pathogen that have entered the body
what are antigens
chemical markers on the outer membrane of an invading pathogen
describe antigens
- proteins or glycoproteins intrinsic to the plasma membrane
- specific to organism
- own cells have antigen but are recognised as our own & don’t produce a response
what are opsonins a type of
antibody
are opsonins specific
some aren’t so can attach to a variety of pathogenic cells
role of opsonins
enhance ability of phagocytic cells to bind & engulf the pathogen
what’s the first line of secondary defence
phagocytosis
what’s the most common phagocytes
neutrophils
what’s the nucleus of neutrophils like
multi-lobed
where are neutrophils manufactured
bone marrow