Question

Complete the passage describing the composition of each tunic that comprises the blood vessel walls. The tunica externa (tunica adventitia) forms the outermost layer of vessel walls and is largely composed of ? which support the vessel by anchoring it to nearby structures. This tunic also contains numerous ? and, in larger vessels, the vasa vasorum. The tunica media, the middle layer, is composed of ? The tunica intima, the innermost layer, is composed of ? In larger vessels, an additional layer comprised of ? provides additional support to the tunica intima.

Answer 1

The tunica externa is composed of connective tissue, the tunica media is composed of smooth muscle, and the tunica intima is composed of endothelium and connective tissue. In larger vessels, elastic fibers provide additional support to the tunica intima.

Step-by-step explanation:

The tunica externa (also called tunica adventitia) forms the outermost layer of vessel walls and is largely composed of connective tissue which support the vessel by anchoring it to nearby structures. This tunic also contains numerous nerves and, in larger vessels, the vasa vasorum. The tunica media, the middle layer, is composed of smooth muscle. The tunica intima, the innermost layer, is composed of endothelium (simple squamous epithelium) and connective tissue. In larger vessels, an additional layer comprised of elastic fibers provides additional support to the tunica intima.