What type of media characterizes large, elastic arteries compared to other artery types?

Large, elastic arteries, such as the aorta and pulmonary arteries, are characterized by a distinct composition that includes a high concentration of elastic fibers. This structural feature is crucial for their function, as it allows these arteries to accommodate the high pressure of blood ejected from the heart during systole and then to recoil during diastole. The elastic fibers enable the arteries to stretch and then return to their original shape, helping to maintain steady blood flow.

In contrast, smaller arteries and arterioles have a higher proportion of smooth muscle relative to elastic fibers. While smooth muscle is important for regulating blood flow and pressure, the predominant characteristic of large elastic arteries is their ability to stretch and recoil, which is facilitated by an abundance of elastic fibers compared to smooth muscle. This specialized composition supports the unique hemodynamic role of large elastic arteries in the cardiovascular system.