Natural Defence Barriers.

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Natural Defence Barriers

Most micro-organisms find it difficult to get inside the body. Without constant defence of our body's barriers we would constantly be ill or even die, as a huge influx of micro-organisms would occur. The body has four main ways of preventing potential illnesses from entering the body.

Chemical Defences - Sweat, tears, saliva and mucus all contain anti-micro-organism chemicals that inhibit their entrance and growth. These secretions all contain vital enzymes that deter the pathogens. These are:

* Lysoozyme - In a bacteria attack this can be found in the bacterium cell walls. Here it catalyses the hydrolysis of the molecule.

* Lactate is contained in sweat and this slows the growth of bacterium.

* The gastric juices of the stomach are in part component of hydraulic acid which is used to dissolve and brake down food in a normal situation. In the presence of bacterium it will do the same.

Mechanical Defences - These are barriers that stop the bacteria from moving further into the body by filtering it. An example of this is the nasal passage. In the nasal passage the nasal hairs filter the air that is drawn