ANATOMY

Detailed explanation-1: -The correct answer is b) Tunica Media. The tunica media is the middle layer present within an arteriole and will be surrounded by the tunica interna on the inside and the tunica externa superficially. The tunica media will be the portion in control of vasoconstriction of the vessel.

Detailed explanation-2: -The tunica media is responsible for vasoconstriction and dilation. This is consistent with answer choice “c". This is the middle layer that is comprised of smooth muscle that allows for the dilation and constriction of the vessel.

Detailed explanation-3: -The smooth muscle found in the tunica media can be stimulated to contract, and this results in vasoconstriction and the narrowing of the blood vessel.

Detailed explanation-4: -Like other blood vessels, arterioles contain only smooth muscle cells in their middle coat, along with other connective tissues, including elastic tissue. Smooth muscle cells are the most abundant component of the tunica media of an arteriole [34].

Detailed explanation-5: -The tunica media is the middle portion of the vessel wall and contains smooth muscle cells and connective tissue, whereas the tunica adventitia is composed of connective tissue that is often continuous with the surrounding soft tissues.