Components of Arterial Walls

Steps:

• Recall that arteries carry blood away from the heart under high pressure, requiring durable structure.
• Identify key layers: tunica intima (endothelium), tunica media (smooth muscle and elastic fibers), tunica adventitia (connective tissue).
• Match options to these layers; arteries lack valves found in veins.
• Select option listing smooth muscle and elastic fibers as primary components.

Why B is correct:

• Arteries contain thick tunica media with smooth muscle and elastic fibers to withstand pressure and regulate flow, per vascular anatomy definitions.

Why the others are wrong:

• A lacks structural elements like elastic fibers needed for arterial elasticity.
• C includes valves, which are absent in arteries but present in veins to prevent backflow.
• D focuses on thin walls typical of capillaries, not arteries.

Not enough information on exact choices, but B aligns with standard anatomy.

Final answer: B