ANATOMY

Detailed explanation-1: -Vasoconstriction is the narrowing (constriction) of blood vessels by small muscles in their walls. When blood vessels constrict, blood flow is slowed or blocked. Vasoconstriction may be slight or severe. It may result from disease, drugs, or psychological conditions.

Detailed explanation-2: -Normally, the vessels that supply blood to the skin constrict or narrow in response to cold temperatures. This reaction, called “vasoconstriction, ” decreases blood flow to the skin, which helps to minimize heat loss from the warm blood and therefore preserve a normal internal or “core” temperature.

Detailed explanation-3: -Vasoconstriction (decreased diameter of vessels) and vasodilation (increased diameter of vessels) are affected by multiple factors.

Detailed explanation-4: -Arteries and arterioles (small arteries) have muscular walls. They’re the main blood vessels involved in vasoconstriction. Veins can also narrow. Capillaries are tiny, thin-walled blood vessels that can’t constrict.