Question

Vital capacity (VC) of our lungs is equal to

• A. inspiratory volume plus expiratory reserve volume
• B. total lung capacity minus residual volume
• C. total lung capacity minus expiratory reserve volume
• D. inspiratory reserve volume plus tidal volume

Answer 1

The correct option is B total lung capacity minus residual volume

Vital capacity is the amount of air which one can inhale or exhale with maximum effort. It is the sum of tidal volume, inspiratory reserve volume and expiratory reserve volume, while total lung capacity is the total amount of air present in the lungs and the respiratory passage after a maximum inspiration. It is the sum of the vital capacity and residual volume.
TLC = VC + RV.
So, vital capacity is also total lung capacity (TLC) - residual volume (RV)