Our blood circulates freely through undamaged, intact vessels. The design of the vasculature, or blood vessels, is such that the walls of the vessels are chemically inert to both coagulation factors and platelets under normal conditions.
Damage to a vessel will break the inert epithelial lining, exposing the subendothelium and collagen, while releasing chemical signals that trigger subsequent hemostatic mechanisms. The first hemostatis mechanism is termed "primary hemostasis".
Overview of the Primary Hemostasis Process:
- Vasoconstriction
- Platelet adhesion
- Platelet activation
- Platelet granule secretion
- Platelet aggregation
- Primary hemostatic plug formation