Hemostasis is the intrinsic process that the body uses to stop
bleeding from an injured vessel. As soon as a vessel is cut or damaged, there
is a reflexive con-striction of the
vessel triggered by chemicals suchas serotonin that are present in platelet
granules and the endothelium of blood vessels. The injured area at-tracts
platelets, which then form a platelet
Meanwhile, a series of events are triggered to form a blood clot in the region.
The semisolid blob of blood we know as a blood clot is actually a
result of a series of complex enzymatic re-actions. While we are thankful for
its formation and prevention of blood loss, it causes alarm if it forms in-side blood vessels or does not form
when bleeding oc-curs. Therefore, the process of clot formation is com-plicated
and must be so finely regulated that blood always stays fluid and clots only
when bleeding occurs. The body has two opposing mechanisms in place—one that
promotes clotting and one that prevents clotting.