The outer layer of a blood vessel that connects it to surrounding tissues is known as the

The outer layer of a blood vessel that connects it to surrounding tissues is known as the

• A. Lumen
• B. Tunica externa
• C. Tunica media
• D. Tunica intima

Answer: (B)

Think about the wall structure of blood vessels. They have three layers, with the outermost one designed to anchor the vessel to surrounding tissues and provide structural support. This layer, called the tunica externa (also known as the adventitia), is made mainly of connective tissue and helps attach the vessel to nearby tissues while sometimes housing small vessels that nourish the vessel wall. The inner lining in contact with the blood is the tunica intima, and the middle layer is the tunica media, which contains smooth muscle and elastic fibers to regulate diameter. The lumen is simply the hollow passage through which blood flows. So the outer layer that connects the vessel to surrounding tissues is the tunica externa.

Think about the wall structure of blood vessels. They have three layers, with the outermost one designed to anchor the vessel to surrounding tissues and provide structural support. This layer, called the tunica externa (also known as the adventitia), is made mainly of connective tissue and helps attach the vessel to nearby tissues while sometimes housing small vessels that nourish the vessel wall. The inner lining in contact with the blood is the tunica intima, and the middle layer is the tunica media, which contains smooth muscle and elastic fibers to regulate diameter. The lumen is simply the hollow passage through which blood flows. So the outer layer that connects the vessel to surrounding tissues is the tunica externa.