MEDICAL PHYSIOLOGY

Detailed explanation-1: -Vasodilation is the widening of blood vessels as a result of the relaxation of the blood vessel’s muscular walls. Vasodilation is a mechanism to enhance blood flow to areas of the body that are lacking oxygen and/or nutrients.

Detailed explanation-2: -Arteries are always under high pressure. To accommodate this stress, they have an abundance of elastic tissue and less smooth muscle. The presence of elastin in the large blood vessels enables these vessels to increase in size and alter their diameter.

Detailed explanation-3: -Definition. Vasoconstriction is the narrowing or even closing of the lumen of a vein, artery, or arteriole as a result of smooth muscle cell constriction in the blood vessel wall. By reducing the diameter of a blood vessel, circulating blood must move through a smaller area under higher pressures.