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 in through breathing. Further on in the breathing process tiny little hairs called cilia beat in a wave like motion to sweep particles away from the lungs. If all else fails mucus is there to catch particles in its viscous solution.

Physical Defences – The skin provides the ultimate all over protection. This physically stops the entry of bacteria. The skin is a combination of dead and living cells. The dead skin cells sit on top of new skin cells protecting it. The thick layer of dead skin cells also contain keratin, a bacterial deterrent, and little water which is vital for the growth of micro-organisms. Healthy skin is rarely penetrated and contains several chemicals that control and prevent bacteria, including:

* Sebum – This contains fatty acids that have anti-bacterial action and is secreted by the sebaceous gland.

* Tears – These dilute and wash away bacteria and irritant chemicals from the eyes. The lachrymal gland secretes this.

* Mucus – A sticky secretion produced by the goblet cells that line the air passages.

Biological Defences – All over our bodies there are colonies of harmless bacteria. Living on our skin there are harmless bacteria and mucous membranes that inhibit the growth of many micro-organisms. They protect us by competing with the bad pathogens for nutrients.

Natural immune defences involve medical intervention for prevention of pathogens, through vaccination or treatment of antibiotics. Antibiotics work by slowing and sometimes stopping the growth and reproduction of colonising pathogen, in some cases destroying them completely. By slowing down the growth of the pathogen, the bodies natural immune system is able to get to work and destroy the illness easily. Vaccines work in a very different way. Vaccination is the process whereby a small amount of an illness is inserted into the patient either orally or by injection. This small dose of bacteria will activate antibodies that are specially equipped and designed to deal with that specific pathogen. This therefore makes the immune response quicker and more effective in the future.

So which method is more effective in the short term? The natural immune system including the skin and mid external protection system, the nasal hairs and serums on the skin that are used in order to combat bacteria are an obvious on contact protection. These are used everyday in the same way and for the majority of the time are very effective in the short term in neutralising bacteria and keeping it out of the bloodstream. But from time to time we may break the continuity of this protection barrier leaving ourselves vulnerable to a number of illnesses and bacteria entering our bodies. When this occurs we often look for a quick solution to remove the bacteria before it has time to infest itself and reproduce. In this situation antibodies are slow to enter into the bloodstream, so to remove the bacteria before it spreads, it is effective to use an antibacterial spray or wash. This will remove all dirt or possible infection quickly and effectively.

Although not always, successful medical intervention of the immune system definitely improves the natural immune system. Both are ineffective without the other and history has shown that medical intervention has improved the health of countries all around the world irradiating dozens of illnesses such as small pox.

In conclusion it is clear to see that alone the natural immune system deals most effectively with minor illnesses such as colds, but in the long term effective prevention has to be sought from vaccinations and antibiotics that reinforce the immune system, making it stronger and more effective.