Vital capacity of lungs is (a) IRV + ERV (b) IRV + ERV + TV – RV (c) IRV + ERV + Tv + RV (d) IRV + ERV + TV
Option D. Vital capacity is maximum amount of air that can be expired forcefully from lungs after maximum deep inspiration. IRV – extra amount of air inhaled forcefully normal inspiration (3000ml) TV – tidal volume of inspiration/expiration during normal breathing (500ml) ERV – extra amount of air expired after normal expiration (1100ml) Therefore, the vital capacity of lungs is 4600ml
