Which of the following lung changes increases with age?

Which of the following lung changes increases with age?

• A. Vital capacity
• B. FEV1
• C. Closing volume
• D. Total lung capacity

Answer: (C)

Aging mainly shifts the balance of airway closure during expiration. As people get older, the lungs lose some elastic recoil and the chest wall stiffens, so the small airways tend to collapse earlier in the expiratory phase. The volume at which these small airways close—the closing volume—increases with age. This means more of the lung closes off at higher lung volumes, promoting air trapping. In contrast, vital capacity tends to decrease with age because inspiratory and expiratory muscles weaken and elastic recoil diminishes. FEV1 also declines with age due to reduced airway elasticity and caliber. Total lung capacity usually stays about the same or may decrease slightly with age, but it does not reliably increase.

Aging mainly shifts the balance of airway closure during expiration. As people get older, the lungs lose some elastic recoil and the chest wall stiffens, so the small airways tend to collapse earlier in the expiratory phase. The volume at which these small airways close—the closing volume—increases with age. This means more of the lung closes off at higher lung volumes, promoting air trapping.

In contrast, vital capacity tends to decrease with age because inspiratory and expiratory muscles weaken and elastic recoil diminishes. FEV1 also declines with age due to reduced airway elasticity and caliber. Total lung capacity usually stays about the same or may decrease slightly with age, but it does not reliably increase.