B3- immune system ( defence) Flashcards
What are 3 PHYSICAL defence mechanisms apart of the PRIMARY IMMUNE SYSTEM?
NOSE: hairs + mucus which trap substances that contain pathogens to prevent entry
SKIN: sebum (oils) coating skin
physical barrier between internal and external environment
EYES: eyelashes protect from dirt and provide physical barrier
What are 3 CHEMICAL defence mechanisms apart of the PRIMARY IMMUNE SYSTEM?
STOMACH ACIDE: bile neutralsies, optimum PH for protease, kills microorganisms
TEARS: contains an enzyme to break down + protect
MUCUS + CILIA: mucus traps pathogens, cilia beats mucus up away (protects lungs)
what are the 2 WBC that defend us against disease
PHAGOCYTES
LYMPHOCYTES
What is phagocytosis
-PATHOGEN binds to CELL MEMBRANE of PHAGOCYTE
-after a PIT is FORMED the phagocyte ENGULFS and DIGESTS pathogen
-pathogen is ABSORBED and DIFFUSED into WBC.
why is phagocytosis considered as a non-specific defence?
phagocyte will engulf ANY PATHOGEN.
what are lymphocytes made up off?
anti-toxins, anti-gens, anti-bodies
what is a antigen?
protein on surface of cell
what is a antibody?
protein produces by lymphocytes to recognise pathogen (through MEMORY CELL) to help clump together.
what is a antitoxin
protein produces to neutralise toxins produced by pathogen (BACTERIA)
why are lymphocytes highly specific?
as antigen have a binding site that fit specifically to the same specific antibody
what do lymphocytes differentiate into?
memory cells
what is a vaccine?
contains a dead or inactive form of a pathogen to cause antibody production and form memory cells.
what is the process of a vaccine?
-vaccine enters body
-lymphocytes produce antibody to fight pathogen
-pathogen destroyed
-now defences against pathogen
-defences= MEMORY CELL
-pathogen dies very quickly if enter body again
what is a painkiller a form of
willow tree
what is a aspirin a form of
mould
