Changes

Thin epithelial surfaces are necessary for the normal physiological functions of the body's mucus membranes (i.e. absorption and gas exchange). They are therefore more susceptible to infection. But the body has a solution by using alternative protective mechanisms in these areas:

Thin epithelial surfaces are necessary for the normal physiological functions of the body's mucus membranes (i.e. absorption and gas exchange). They are therefore more susceptible to infection. But the body has a solution by using alternative protective mechanisms in these areas:

*  The '''mucociliary escalator''' of the respiratory tract (assisted by coughing and sneezing)

*  The [[Respiratory Epithelium - Anatomy & Physiology|'''mucociliary escalator''']] of the respiratory tract (assisted by coughing and sneezing)

* '''Peristalsis, vomiting & diarrhoea''' when necessary removes microorganisms from the Gastro-Intestinal Tract

* '''Peristalsis, [[vomiting]] & diarrhoea''' when necessary removes microorganisms from the gastro-intestinal tract

===Biochemical Barriers===

===Biochemical Barriers===

Where there are breaks in the skin that are open to the outside environment the body has an armoury of biochemical barriers that can stop infection. These are:  

Where there are breaks in the skin that are open to the outside environment the body has an armoury of biochemical barriers that can stop infection. These are:  

* '''Lactic and fatty acids''' in sweat and sebaceous secretions are directly bacteriocidal

* '''Lactic and fatty acids''' in sweat and sebaceous secretions are directly bacteriocidal

* '''Enzymes''' e.g. lysozyme in saliva, sweat & tears and Gastric acid denature microorganisms

* '''Enzymes''' e.g. lysozyme in saliva, sweat & tears and gastric acid denature microorganisms

* Mucous itself is acidic, indigestible and traps microorganisms

* Mucous itself is acidic, indigestible and traps microorganisms

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{{Jim Bee 2007}}

{{Jim Bee 2007}}

[[Category:Innate Immune System]]

[[Category:Innate Immune System]]