Non-Specific Defences

• Tears - contain enzymes that will destroy any pathogens that make contact with the eye.
• Stomach acid - hydrochloric acid, produced by glands in the stomach wall to destroy pathogens that enter the stomach.
• Mucus - produced in the respiratory system and traps particles and bacteria entering the airways.
• Skin - a waterproof barrier that pathogens cannot pass through.

  Good bacteria live permanently on the skin and prevent pathogens from growing there.