In pulmonary function testing, which option best describes the Forced Vital Capacity (FVC)?

In pulmonary function testing, which option best describes the Forced Vital Capacity (FVC)?

• A. Residual volume remaining after maximal expiration.
• B. Forced vital capacity: total volume exhaled during maximal expiration.
• C. Total lung capacity during full inspiration.
• D. Volume exhaled in the first second of expiration.

Answer: (B)

Forced Vital Capacity is the total amount of air that can be forcibly exhaled after taking the deepest possible breath. This means it measures the overall volume expelled during a maximal, forced expiration starting from full inspiration. The option describing this exact idea—total volume exhaled during a maximal forced expiration after full inhalation—is the best match. Residual volume is what stays in the lungs after a complete exhale and is not emitted during the maneuver. Total lung capacity during full inspiration refers to the maximum air the lungs can hold, not what is expelled. The volume exhaled in the first second of expiration is the FEV1, which reflects rate of flow, not the total exhaled volume.

Forced Vital Capacity is the total amount of air that can be forcibly exhaled after taking the deepest possible breath. This means it measures the overall volume expelled during a maximal, forced expiration starting from full inspiration. The option describing this exact idea—total volume exhaled during a maximal forced expiration after full inhalation—is the best match. Residual volume is what stays in the lungs after a complete exhale and is not emitted during the maneuver. Total lung capacity during full inspiration refers to the maximum air the lungs can hold, not what is expelled. The volume exhaled in the first second of expiration is the FEV1, which reflects rate of flow, not the total exhaled volume.