Which statement correctly contrasts stenotic and incompetent valves?

Which statement correctly contrasts stenotic and incompetent valves?

• A. Stenotic valves leak backward; incompetent valves narrow.
• B. Stenotic valves close fully; incompetent valves never leak.
• C. Stenotic valves narrow and harden; incompetent valves cannot close fully, allowing backflow.
• D. Both types reduce forward flow equally.

Answer: (C)

Stenosis narrows and stiffens a valve, reducing forward blood flow and often raising pressure upstream. Incompetence (insufficiency) means the valve cannot close fully, so blood leaks backward when it should be sealed. Together, that distinction is exactly what the correct statement conveys: stenotic valves narrow and harden, while incompetent valves cannot close fully, allowing backflow. The other ideas mix up which condition causes narrowing versus leakage.

Stenosis narrows and stiffens a valve, reducing forward blood flow and often raising pressure upstream. Incompetence (insufficiency) means the valve cannot close fully, so blood leaks backward when it should be sealed. Together, that distinction is exactly what the correct statement conveys: stenotic valves narrow and harden, while incompetent valves cannot close fully, allowing backflow. The other ideas mix up which condition causes narrowing versus leakage.