Which term describes the air left in the lungs after a full exhalation?

Which term describes the air left in the lungs after a full exhalation?

• A. Tidal Volume
• B. Inspiratory Reserve Volume
• C. Expiratory Reserve Volume
• D. Residual Volume

Answer: (D)

Residual volume is the amount of air left in the lungs after a full exhalation. This is the air that cannot be expelled even with maximal effort because the lungs and airways never become completely empty, and leaving some air helps keep the alveoli open for gas exchange between breaths. It differs from tidal volume (the normal breath in and out), inspiratory reserve volume (extra air you can inhale beyond a normal inhalation), and expiratory reserve volume (extra air you can exhale beyond a normal exhalation). Residual volume also contributes to the functional residual capacity (FRC = ERV + RV) and isn’t measured with a standard spirometer.

Residual volume is the amount of air left in the lungs after a full exhalation. This is the air that cannot be expelled even with maximal effort because the lungs and airways never become completely empty, and leaving some air helps keep the alveoli open for gas exchange between breaths. It differs from tidal volume (the normal breath in and out), inspiratory reserve volume (extra air you can inhale beyond a normal inhalation), and expiratory reserve volume (extra air you can exhale beyond a normal exhalation). Residual volume also contributes to the functional residual capacity (FRC = ERV + RV) and isn’t measured with a standard spirometer.