Aging affects cardiac muscle strength by what change?

Aging affects cardiac muscle strength by what change?

• A. Decrease
• B. Increase
• C. Stay the same
• D. Fluctuate

Answer: (A)

As people age, the heart’s pumping strength tends to weaken. Structural and cellular changes drive this: there’s a loss of heart muscle cells and an increase in fibrous tissue, which makes the myocardium stiffer and less able to contract forcefully. Calcium handling and the heart’s responsiveness to sympathetic signals can also decline, further reducing contractile strength. Because of these changes, maximum stroke volume and overall cardiac output—especially during activity—tend to decrease, even if resting function is still adequate in many individuals. That’s why the change is a decrease in cardiac muscle strength with aging. The other options don’t fit because aging does not typically cause stronger contraction, exact unchanged strength, or fluctuating strength as the general pattern.

As people age, the heart’s pumping strength tends to weaken. Structural and cellular changes drive this: there’s a loss of heart muscle cells and an increase in fibrous tissue, which makes the myocardium stiffer and less able to contract forcefully. Calcium handling and the heart’s responsiveness to sympathetic signals can also decline, further reducing contractile strength. Because of these changes, maximum stroke volume and overall cardiac output—especially during activity—tend to decrease, even if resting function is still adequate in many individuals. That’s why the change is a decrease in cardiac muscle strength with aging. The other options don’t fit because aging does not typically cause stronger contraction, exact unchanged strength, or fluctuating strength as the general pattern.