Final answer:
Muscular arteries, with abundant smooth muscle in the tunica media, branch out to regulate blood flow to arterioles through vasoconstriction. They adapt to lower pressures farther from the heart and are key to the myogenic response, ensuring consistent blood flow.
Step-by-step explanation:
Muscular arteries are blood vessels with abundant smooth muscle in the tunica media that branch out to distribute blood to arterioles. These arteries play a key role in regulating blood flow through vasoconstriction and are also known as distributing arteries because they manage the distribution of blood to various parts of the body via the arteriole network.
The myogenic response is a mechanism of these arteries that involves constriction or dilation in response to changes in blood pressure to maintain consistent flow to the capillary network. Another feature is the presence of nervi vasorum, small nerve fibers that trigger the contraction of the smooth muscle in the walls of these arteries.
Muscular arteries are characterized by a decrease in elastic fibers and an increase in smooth muscle compared to elastic arteries, adapting them for their role farther from the heart where blood pressure is lower. The thick tunica media of muscular arteries allows them to significantly contribute to vasoconstriction, whereas their reduced elasticity makes them less suited for expansion compared to elastic arteries.