Primary lines of Defence

Skin
1. Impermeable to most pathogens
  1. Some can penetrate
    1. Viruses that create warts
2. 'Flora' of harmless bacteria
  1. Live on healthy skin
3. Most pathogenic bacteria cannot survive in skin
  1. Lactic + fatty acids secreted by sweat glands
    1. pH is too low for them
4. Damaged skin is an entrance for harmful bacteria
  1. Underlying tissue
  2. Blood clotting seals wounds quickly
Vagina
1. Bacterium keep pH low by secreting lactic acid
  1. These bacteria can be killed by using antibiotics
    1. pH of vagina rises, allowing other microorganisms to multiply more
Eyes + Mouth
1. Bathed in fluids which have bactericidal action
  1. Lysozyme
    1. Saliva + Tears
    2. Enzyme that destroys/damages many bacteria
Semen
1. Spermine
Breast milk
1. Lactoperoxidase
Stomach
1. Hydrochloric acid
  1. Destroys/damages bacteria ingested in food
Mucus
1. Protects digestive and respiratory tracts from infection
  1. Barrier
    1. Bacteria cannot make contact with epithelial cells lining walls of tubes
  2. Traps bacteria and other particles
2. Produced by goblet cells

Resource summary

	Created by Lily Page over 11 years ago