Question

fill in the blank question
vasoconstriction primarily results from contraction of smooth muscle in the tunica

Explanation:

In blood vessel anatomy, the tunica media is the middle layer of a blood vessel wall that contains smooth muscle. Contraction of this smooth muscle leads to vasoconstriction (narrowing of the blood vessel). The tunica intima is the inner lining, and tunica externa is the outer connective tissue layer, neither of which has the smooth muscle responsible for vasoconstriction.

Answer:

media