Which type of muscle fiber is predominantly found in arterial walls?

Smooth muscle fiber is predominantly found in arterial walls. This type of muscle fiber is characterized by its involuntary nature and its ability to contract and relax to regulate blood vessel diameter and thus blood flow. Smooth muscle fibers are non-striated, which is a key distinguishing feature from cardiac and skeletal muscles, both of which are striated.

The function of smooth muscle in arteries is crucial for maintaining blood pressure and controlling blood flow to various organs based on their metabolic needs. As the smooth muscle contracts, it narrows the lumen of the arteries (vasoconstriction), which increases blood pressure. When it relaxes (vasodilation), the lumen widens, allowing more blood to flow through and decreasing blood pressure.

Cardiac muscle, while essential for heart function, is not found in arterial walls; it is found exclusively in the heart. Skeletal muscle is under voluntary control and is attached to bones, also not present in the walls of arteries. The term "rough" does not refer to a type of muscle fiber in human anatomy and thus is not applicable in this context.