Inflammation
<p ><b>Inflammation</b> (<a href="http://en.wikipedia.org/wiki/Latin" title="Latin" >Latin</a>, <i><a href="http://en.wiktionary.org/wiki/en:inflammo#Latin" class="extiw" title="wikt:en:inflammo" >īnflammō</a></i>, "I ignite, set alight") is part of the complex biological response of <a href="http://en.wikipedia.org/wiki/Blood_vessel" title="Blood vessel" >vascular</a> tissues to harmful stimuli, such as <a href="http://en.wikipedia.org/wiki/Pathogen" title="Pathogen" >pathogens</a>, damaged cells, or irritants.<sup id="cite_ref-pmid17223962_0-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Inflammation#cite_note-pmid17223962-0" >[1]</a></sup> Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process. Inflammation is not a synonym for <a href="http://en.wikipedia.org/wiki/Infection" title="Infection" >infection</a>, even in cases where inflammation is caused by infection. Although infection is caused by a microorganism, inflammation is one of the responses of the organism to the pathogen. However, inflammation is a stereotyped response, and therefore it is considered as a mechanism of <a href="http://en.wikipedia.org/wiki/Innate_immune_system" title="Innate immune system" >innate immunity</a>, as compared to <a href="http://en.wikipedia.org/wiki/Adaptive_immune_system" title="Adaptive immune system" >adaptive immunity</a>, which is specific for each pathogen.<sup id="cite_ref-ABBAS_1-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Inflammation#cite_note-ABBAS-1" >[2]</a></sup></p>
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Without inflammation, wounds and infections would never heal.<sup class="Template-Fact" >[<i><a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a></i>]</sup> Similarly, progressive destruction of the tissue would compromise the survival of the organism. However, chronic inflammation can also lead to a host of diseases, such as <a href="http://en.wikipedia.org/wiki/Hay_fever" title="Hay fever" class="mw-redirect" >hay fever</a>,<a href="http://en.wikipedia.org/wiki/Periodontitis" title="Periodontitis" >periodontitis</a>, <a href="http://en.wikipedia.org/wiki/Atherosclerosis" title="Atherosclerosis" >atherosclerosis</a>, <a href="http://en.wikipedia.org/wiki/Rheumatoid_arthritis" title="Rheumatoid arthritis" >rheumatoid arthritis</a>, and even cancer (e.g., <a href="http://en.wikipedia.org/wiki/Gallbladder_carcinoma" title="Gallbladder carcinoma" class="mw-redirect" >gallbladder carcinoma</a>). It is for that reason that inflammation is normally closely regulated by the body.</p>
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Inflammation can be classified as either <i>acute</i> or <i>chronic</i>. <i>Acute inflammation</i> is the initial response of the body to harmful stimuli and is achieved by the increased movement of <a href="http://en.wikipedia.org/wiki/Blood_plasma" title="Blood plasma" >plasma</a> and <a href="http://en.wikipedia.org/wiki/Leukocyte" title="Leukocyte" class="mw-redirect" >leukocytes</a> (especially <a href="http://en.wikipedia.org/wiki/Granulocyte" title="Granulocyte" >granulocytes</a> ) from the blood into the injured tissues. A cascade of biochemical events propagates and matures the inflammatory response, involving the local <a href="http://en.wikipedia.org/wiki/Vascular_system" title="Vascular system" class="mw-redirect" >vascular system</a>, the <a href="http://en.wikipedia.org/wiki/Immune_system" title="Immune system" >immune system</a>, and various cells within the injured tissue. Prolonged inflammation, known as <i>chronic inflammation</i>, leads to a progressive shift in the type of cells present at the site of inflammation and is characterized by simultaneous destruction and <a href="http://en.wikipedia.org/wiki/Healing" title="Healing" >healing</a> of the tissue from the inflammatory process.</p>