The body’s defence mechanisms

////The body’s defence mechanisms

The body’s defence mechanisms

Image credit keyword-suggestions.com

Image credit keyword-suggestions.com

ZIMSEC O Level Combined Science Notes: Disease:The body’s defence mechanisms

  • The body is equipped to deal with and defend itself against diseases and infections
  • These defends, while inadequate, are effective and essential
Some of the body's defenses. Image credit schoolbag.info

Some of the body’s defenses. Image credit schoolbag.info

  • Skin-is a physical barrier against all bacteria and other pathogens
  • Wax and hairs-found in the ears prevent invasion by microorganisms
  • Mucus and hairs-found in the nose trap invading bacteria and spores
  • Stomach acids-they kill bacteria in the food
  • White blood cells-some of them engulf and digest bacteria while others produce antibodies to destroy bacteria/neutralise toxins/poisons produced by bacteria
  • Tears-have a mild antiseptic to kill bacteria in the eyes
  • Blood clotting-is caused by platelets in the blood at damaged parts of the skin. This involves blood proteins in the plasma forming a network of fibres and eventually clotting. Clotting also helps prevent loss of blood.
  • Saliva-it has a cleansing action

To access more topics go to the Combined Science Notes page

By |2017-01-17T11:11:35+00:00August 16th, 2016|Notes, O Level Science Notes, Ordinary Level Notes|Comments Off on The body’s defence mechanisms

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He holds an Honours in Accountancy degree from the University of Zimbabwe. He is passionate about technology and its practical application in today's world.
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