When skin is damaged

When skin is damaged -...

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When skin is damaged, for example, and bacteria, other organisms, or toxic  substances enter the body, the following events occur: A chemical alarm is generated in the injured area. Injured cells and nearby circulating  cells release chemicals that initiate defensive actions and sound an alarm to other  defense mechanisms. These chemicals include histamine (mostly secreted by  basophils, white blood cells found in connective tissue), kinins, prostaglandins (PGs),  and complement proteins. Vasodilation  (dilation of blood vessels), stimulated by histamine and other  chemicals, increases blood supply to the damaged area. This causes redness and an  increase in local temperature. The increase in temperature stimulates white blood  cells and makes the environment inhospitable to pathogens.  Vascular permeability increases in response to alarm chemicals. As a result, white 
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This note was uploaded on 11/10/2011 for the course PT 101 taught by Professor Staff during the Spring '10 term at Texas State.

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