- Narrowing of the blood vessels resulting from contracting of the muscular wall of the vessels. The opposite of vasodilation.
* * *Narrowing of the blood vessel s.- active v. reduced caliber of a vessel caused by increased tonus in the smooth muscle in its walls.
* * *va·so·con·stric·tion -kən-'strik-shən n narrowing of the lumen of blood vessels esp. as a result of vasomotor action
* * *n.a decrease in the diameter of blood vessels, especially arteries. This results from activation of the vasomotor centre in the brain, which brings about contraction of the muscular walls of the arteries and hence an increase in blood pressure.
* * *vaso·con·stric·tion (va″zo-) (vas″o-kən-strikґshən) the diminution of the caliber of vessels, especially constriction of arterioles leading to decreased blood flow to a part. vasoconstrictive adj
Medical dictionary. 2011.