Question

What is vital capacity of our lungs?

• A. Inspiratory reserve volume plus tidal volume
• B. Total lung capacity minus expiratory reserve volume
• C. Inspiratory reserve volume plus expiratory reserve volume
• D. Total lung capacity minus residual volume

Answer 1

Answer: (D)

Vital capacity of lungs is the largest possible expiration after largest possible inspiration that is greatest. Volume of air can be exchanged in single respiration or amount of air breathed in and out with greatest possible efforts.
Vital capacity = TV + IRV + ERV
Total lung capacity = VC + RV
So we can say that VC = Total lung capacity - Residual volume