Studied by 2 people
pathogen
is a disease - causing microorganism
types of pathogens
bacterium, fungus, virus
example of infection routes into body
contaminated food and drink, infected wounds, droplets breathed in
two types of defence systems in body
the general defence system and the specific defence system
general defence system
involves barriers and non-specific cell responses. it does not fight particular pathogens
description of skin
structural barrier
function of skin
prevents entry of pathogens
description of sweat
contains the enzyme lysozyme
function of sweat
kill pathogens
description of mutualistic bacteria
found of the skin and in the large intestine (colon)
function of mutualistic bacteria
stop harmful microorganisms growing
description of sebum
natural moisturiser (oil) produced by the sebaceous glands in skin
function of sebum
stops the skin cracking (opening)
description of acid
hydrochloric acid in stomach, lactic acid in vagina
function of acid
kills pathogens
description of mucus
in the breathing, digestive and reproductive system
function of mucus
traps pathogens
description of fever
high temperature
function of fever
denatures enzymes in the pathogen, destroying it
description of white blood cells
(called phagocytes/macrophages)
function of white blood cells
engulf pathogens by phagocytosis
description of platelets
clot blood when skin is cut
function of platelets
stops pathogens entering the body
description of histamine (blood)
chemical produced body cells
function of histamine (blood)
causes inflammation - blood vessels dilate so it is easier for white blood cells to get to the area of infection
description of interferon (blood)
chemical that body cells produce when they are infected by a virus
function of interferon (blood)
stops viral replication and so stop virus spreading
description of complement proteins (blood)
found in blood plasma
function of complement proteins (blood)
makes holes in the pathogens and burst them
the specific defence system
distinguishes between different pathogens and responds to each particular one
