The first specific, recognizable hemostatic mechanism is a process known as vasoconstriction, which is initiated by chemical signals stemming from a breach of the vasculature.
Vasoconstriction, or vascular constriction, immediately reduces the quantity of blood flowing through the damaged area. Its action is the physical decrease in the size of the vessel and the redirection of blood flow around and away from the damaged area. Vasoconstriction is akin to putting a clamp on a pliable piece of plastic tubing.
A short process in terms of the overall time elapsed, the entire vascular response typically lasts less than one minute! Though fleeting, vasoconstriction is an exceedingly important hemostatic mechanism as it prepares the damaged vessel for subsequent repair activities.
