Difference between revisions of "Human Defences Against Micro-Organism"
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: The eyelids sweep [[micro-organism]]s from the surface of the [[eye]]s. | : The eyelids sweep [[micro-organism]]s from the surface of the [[eye]]s. | ||
: The eyelashes prevent some [[micro-organism]]s getting into the [[eye]]s. | : The eyelashes prevent some [[micro-organism]]s getting into the [[eye]]s. | ||
| − | : The | + | : The tear ducts produce [[Lysosome]]s which are [[antimicrobial]] [[chemical]]s. |
===The Stomach=== | ===The Stomach=== | ||
: The [[stomach]] is kept at a very low [[pH]] with [[Hydrochloric Acid]] which kills most [[micro-organism]] which enter the [[stomach]]. | : The [[stomach]] is kept at a very low [[pH]] with [[Hydrochloric Acid]] which kills most [[micro-organism]] which enter the [[stomach]]. | ||
Revision as of 19:16, 3 April 2019
Contents
Key Stage 4
Meaning
Human defences against micro-organisms are all the ways the human body can prevent infection by a pathogen.
About Human Defences against Micro-organisms
Defences against micro-organisms can be broken down into two main groups: Chemical Defences and Physical Barriers.
The Skin
- The human body is covered in skin which acts as a physical barrier to prevent micro-organisms from getting into the blood or organs.
- The skin has sweat glands which produce sweat which contains antimicrobial chemicals which can kill pathogens.
- When the skin is cut the blood can clot to produce another physical barrier to stop pathogens getting into the body.
The Nose
- The nose has hairs which act as a physical barrier as they can trap microorganisms before they enter the lungs.
- The nose is full of mucus which acts as a physical barrier since it is a sticky substance which microorganisms can get stuck in. This mucus is then swallowed into the harsh environment of the stomach which kills microorganisms.
The Trachea
- The trachea is full of mucus which acts as a physical barrier since it is a sticky substance which microorganisms can get stuck in. This mucus is then swept up away from the lungs by Ciliated Epithelial Cells into the throat where it is then swallowed into the harsh environment of the stomach which kills microorganisms.
The Eyes
- The eyelids sweep micro-organisms from the surface of the eyes.
- The eyelashes prevent some micro-organisms getting into the eyes.
- The tear ducts produce Lysosomes which are antimicrobial chemicals.
The Stomach
- The stomach is kept at a very low pH with Hydrochloric Acid which kills most micro-organism which enter the stomach.