Final answer:
More elastic fibers would be found in the elastic artery, which is closer to the heart. Elastic arteries have abundant elastic fibers allowing for expansion and recoil, whereas muscular arteries have more smooth muscle and fewer elastic fibers, as they are farther from the heart.
Step-by-step explanation:
When comparing an elastic and muscular artery, more elastic fibers would be found in the elastic artery. Elastic arteries are vessels that conduct blood away from the heart and have a high percentage of elastic fibers. Vessels larger than 10 mm in diameter, such as the aorta and its primary branches, are typically elastic arteries. They have thick walls with abundant elastic fibers that enable them to expand and recoil as blood is pumped through them. This helps maintain the pressure gradient needed for blood flow and reduces the workload on the heart.
In comparison, muscular arteries, also known as distributing arteries, have a higher proportion of smooth muscle in their tunica media and a decrease in the percentage of elastic fibers as they are farther from the heart. The reduced quantity of elastic fibers limits their ability to expand, but since blood pressure has eased by the time it reaches these vessels, elasticity is less crucial. Therefore, the presence of a high percentage of elastic fibers is a characteristic of elastic arteries that are closer to the heart.