Question

If the figure shown is an elastic artery, what layer is the letter A representing?
A) tunica adventitia. 
B) tunica intima. 
C) tunica media.

Accepted Answer

The elastic artery is characterized by the presence of elastic fibers throughout its wall, especially in the tunica media. Layer A in the figure represents the tunica media, which is composed of smooth muscle cells and elastic fibers. Therefore, choice C is the correct answer. The tunica adventitia (choice A) is the outermost layer of the artery, consisting of connective tissue, while the tunica intima (choice B) is the innermost layer, composed of endothelial cells and a thin layer of connective tissue. However, neither of these layers corresponds to the letter A in the figure.