Editing Thrombosis (section)

==== Endothelial cell injury ====
Any inflammatory process, such as trauma, surgery or infection, can cause damage to the [[endothelium|endothelial lining]] of the vessel's wall. The main mechanism is exposure of [[tissue factor]] to the blood coagulation system.<ref name="labtestsonline">[http://www.labtestsonline.org/understanding/conditions/hypercoagulable_disorders-3.html labtestsonline > Hypercoagulable Disorders] {{Webarchive|url=https://web.archive.org/web/20070618165003/http://www.labtestsonline.org/understanding/conditions/hypercoagulable_disorders-3.html |date=June 18, 2007 }} This article was last reviewed on May 23, 2007, and was last modified on March 6, 2010.</ref> Inflammatory and other stimuli (such as [[hypercholesterolemia]]) can lead to changes in [[gene expression]] in endothelium producing to a pro-thrombotic state.<ref name=":0" /> When this occurs, endothelial cells [[Downregulation and upregulation|downregulate]] substances such as [[thrombomodulin]], which is a key modulator of thrombin activity.<ref>{{Cite journal|last1=Ito|first1=Takashi|last2=Kakihana|first2=Yasuyuki|last3=Maruyama|first3=Ikuro|date=January 1, 2016|title=Thrombomodulin as an intravascular safeguard against inflammatory and thrombotic diseases|journal=Expert Opinion on Therapeutic Targets|volume=20|issue=2|pages=151–158|doi=10.1517/14728222.2016.1086750|issn=1744-7631|pmid=26558419|s2cid=207486815}}</ref> The result is a sustained activation of thrombin and reduced production of [[protein C]] and tissue factor inhibitor, which furthers the pro-thrombotic state.<ref name=":0" />

Endothelial injury is almost invariably involved in the formation of thrombi in arteries, as high rates of blood flow normally hinder clot formation. In addition, arterial and cardiac clots are normally rich in platelets–which are required for clot formation in areas under high stress due to blood flow.<ref name=":0">{{Cite book|title=Robbins and Cotran Pathologic Basis of Disease|last=Kumar|first=Vinay|publisher=Elsevier|year=2015|isbn=978-1-4557-2613-4|location=Philadelphia|pages=122–130}}</ref>