Definition
- Hemostasis is the physiological process that arrests bleeding from an injured blood vessel, occurring in three sequential stages: vasoconstriction, temporary hemostatic plug formation and blood coagulation.
Mechanisms of hemostasis, overview flow
Vasoconstriction
- Vasoconstriction is the immediate response of an injured blood vessel, limiting blood loss at the site.
- Initially a mechanical, stretch-induced contraction of vascular smooth muscle; later, vasoconstriction is maintained and potentiated by vasoconstrictor substances secreted from activated platelets.