Consists of fibrin gels in which the formed elements of the blood, principally the red cells, are passively trapped. Clots are derived from extravascular coagulation whether that occurs in vitro (laboratory testing), by shedding (initiated by vessel injury) of blood into tissues or body cavities, or after death (postmortem clot). Clots are dark red, elastic, and moist with a glistening surface. Though commonly used as interchangeable terms, blood clot and thrombus are not synonymous.
