Which term refers to the amount of air left in the lungs after complete exhalation?

Which term refers to the amount of air left in the lungs after complete exhalation?

• A. Tidal volume
• B. Residual volume
• C. Vital capacity
• D. Total lung capacity

Answer: (B)

Breathing involves different lung volumes, and this question asks about the air that remains in the lungs after you have expelled as much as you can. That air is residual volume. It’s the amount that stays in the lungs to keep the airways open and to prevent the lungs from collapsing between breaths, which helps maintain a continuous surface for gas exchange. To place it in context: tidal volume is the usual breath you take at rest, the amount you inhale and exhale in normal breathing. Vital capacity is the maximum amount you can exhale after a full inhalation, which combines several volumes. Total lung capacity is all the air the lungs can hold when you breathe in fully, including the air that remains after you exhale (the residual volume). Because some air must always remain in the lungs, residual volume is the correct term for air left after complete exhalation.

Breathing involves different lung volumes, and this question asks about the air that remains in the lungs after you have expelled as much as you can. That air is residual volume. It’s the amount that stays in the lungs to keep the airways open and to prevent the lungs from collapsing between breaths, which helps maintain a continuous surface for gas exchange.

To place it in context: tidal volume is the usual breath you take at rest, the amount you inhale and exhale in normal breathing. Vital capacity is the maximum amount you can exhale after a full inhalation, which combines several volumes. Total lung capacity is all the air the lungs can hold when you breathe in fully, including the air that remains after you exhale (the residual volume). Because some air must always remain in the lungs, residual volume is the correct term for air left after complete exhalation.