Pathogenesis of thrombosis.

The hemostatic process is a host defense mechanism to preserve the integrity of the closed high pressure circulatory system. This process must remain inactive but poised to minimize extravasation of blood from the vasculature following tissue injury. Given the complexity of the hemostatic mechanism, paradigms developed from biochemical and cell biological approaches have been revisited by studying thrombus formation in a live animal by intravital microscopy. Many of these paradigms have proven accurate, but others need to be reconsidered given the results of whole animal experiments.