Minimal volume is defined as which of the following?

Minimal volume is defined as which of the following?

• A. Air at the end of normal respiration.
• B. The air that cannot be forcibly exhaled.
• C. Air remaining after residual volume.
• D. The maximum amount of air that can be inhaled after complete expiration.

Answer: (C)

Minimal volume refers to the smallest amount of air the lungs can contain, which occurs after a maximal exhalation when the lungs and chest wall recoil to their smallest size. This air is the air that cannot be expelled with a forced breath—the air left in the lungs after you’ve exhaled as much as possible. In practice, that leftover air corresponds to the residual volume, the volume you can’t exhale. The other options describe other lung volumes: the air at the end of normal expiration is the functional residual capacity, the maximum air you can inhale after complete expiration is the inspiratory (or tidal) reserve, and the air that cannot be exhaled fits best with residual volume.

Minimal volume refers to the smallest amount of air the lungs can contain, which occurs after a maximal exhalation when the lungs and chest wall recoil to their smallest size. This air is the air that cannot be expelled with a forced breath—the air left in the lungs after you’ve exhaled as much as possible. In practice, that leftover air corresponds to the residual volume, the volume you can’t exhale. The other options describe other lung volumes: the air at the end of normal expiration is the functional residual capacity, the maximum air you can inhale after complete expiration is the inspiratory (or tidal) reserve, and the air that cannot be exhaled fits best with residual volume.