Tags: Anatomical Structure.
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels in particular the large arteries and small arterioles. The process is the opposite of vasodilation the widening of blood vessels. The process is particularly important in staunching hemorrhage and acute blood loss. When blood vessels constrict the flow of blood is restricted or decreased thus retaining body heat or increasing vascular resistance.