How does aging affect arterial compliance and pulse pressure?

• A. Arteries become more compliant with age.
• B. Pulse pressure decreases with age.
• C. Arteries stiffen with age due to elastin degradation and collagen deposition, increasing systolic BP and pulse pressure; baroreceptor sensitivity decreases.
• D. Baroreceptors become more sensitive with age, reducing BP variability.

Answer: (C)

Aging reduces arterial compliance because elastic fibers in the arterial walls break down and are replaced by stiffer collagen. This makes arteries less able to stretch when the heart ejects blood, so they don’t dampen the pressure as well. As a result, systolic blood pressure tends to rise while diastolic pressure may not rise as much, leading to a wider pulse pressure. At the same time, baroreceptors—our pressure sensors—become less sensitive with age, so the reflex buffering of blood pressure changes is diminished and variability can increase. So the overall pattern is stiffer arteries with higher systolic pressure and a larger pulse pressure, plus reduced baroreceptor sensitivity.

The other ideas don’t fit the physiology: arteries don’t become more compliant with age; pulse pressure doesn’t typically decrease with aging; and baroreceptors don’t become more sensitive over time.