Non-specific/physical and chemical barriers

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  • Created by: samnt987
  • Created on: 01-03-16 19:03

The first line of defence is a combination of physical and chemical barriers that prevent all type of foreign substance from entering the body, so is called ‘non-specific’. These are:

  • The skin is a tough, impenetrable barrier, as for example the epidermis is 20 to 30 cells thick and the cells are toughened by keratin (protein)
  • Sweat and tears (secreted by glands in the skin) contains lysozyme enzymes which destroy (lyse) bacteria growing on the surface of the skin by digesting their cell walls
  • The digestive tract


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