Question

Differentiate between vital lung capacity and total lung capacity.

Answer 1

• Vital capacity is the maximum amount of air that can be voluntarily moved into or out of the respiratory system with one breath, and is the sum of the inspiratory reserve volume, expiratory reserve volume, and tidal volume.

Vital capacity (VC) = IRV + ERV + VT

• The total lung capacity is the sum of the vital capacity and the residual volume (volume of air in the respiratory system after maximal exhalation).

Total lung capacity (TLC) = VC + RV