Question

The amount of air that moves in or out of the lungs with each respiratory cycle is:

• A. Inspiratory reserve volume
• B. Expiratory reserve volume
• C. Tidal volume
• D. Residual volume

Hint:

Tidal volume (TV) is the air exchanged during each normal breath, approximately 500 mL in an average adult.

Answer 1

The Correct Option is C

Total lung capacity can be split into four separate volumes, and each one covers a different part of the breathing cycle. Sorting the options into that picture makes the answer clear.

1. Inspiratory reserve volume: The bonus air available for a deep inhalation, sitting above the normal breath rather than being part of it.
2. Expiratory reserve volume: The bonus air available for a forced exhalation, sitting below the normal breath rather than being part of it.
3. Tidal volume: The band of air right in the middle, the amount breathed in and then back out with every single quiet, resting breath, which is exactly the normal respiratory cycle the question is asking about.
4. Residual volume: The air permanently left behind after full exhalation, keeping the lungs from collapsing, but it never leaves or enters during breathing.

Since the question is asking about ordinary, everyday breathing rather than a forced maximal breath, the volume it is describing is the tidal volume. The correct answer is Tidal volume.