Question

Complete the following blanks, regarding lung volumes and capacities.
i. Functional lung capacity (FRC)$⟶$ ERV+RV= ________.
ii. Inspiratory capacity (IC)$⟶$ TV+IRV= ________.
iii. Vital capacity (VC)$⟶$ IC+ERV= ________.
iv. Total lung capacity $⟶$ RV+VC= ________.

• A. i. 2,400 ii. 3,500 iii. 4,700 iv. 5,900
• B. i. 5,900 ii. 2,400 iii. 3,500 iv. 4,700
• C. i. 3,500 ii. 4,700 iii. 2,400 iv. 5,900
• D. i. 2,400 ii. 4,700 iii. 3,500 iv. 5,900

Answer 1

The correct option is A

i. 2,400 ii. 3,500 iii. 4,700 iv. 5,900

Functional lung capacity is the volume of air remaining in the lungs after a normal expiration. This value is equal to the ERV + RV which is 1,200 ml + 1,200 ml or 2,400 ml. Inspiratory capacity is the maximum volume of air, a person can inspire after a normal expiration. It can be calculated by adding IRV which is 3,000ml with the tidal volume, TV which is 500ml (IRV + TV = 3,500ml). The third capacity is vital capacity. This is the maximum amount of air a person can expire after a forced inspiration. It can be calculated by adding the inspiratory capacity (IC), which is 3,500ml, with the expiratory reserve volume (ERV) which is 1,200ml (IC + ERV = 4,700ml). Total lung capacity is the maximum volume of air the lung can hold. This is basically the vital capacity which is 4,700 ml plus the residual volume which is 1,200ml (RV + VC = 5,900ml).