Question

What is the vital capacity of our lungs?
A. Inspiratory reserve volume plus functional residual capacity
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

Hint: The lung capacity is the respiratory capacity. It indicates the volume of gas present in the lungs at the respective respiratory cycle.

Complete answer:
The lungs' vital capacity can be defined as the maximum amount of air exhaled by the body after maximum inhalation. The lung capacity of the individual is 4800 mL approximately. The vital capacity is the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume.
On the contrary, total lung capacity is the sum of residual volume, tidal volume, inspiratory reserve volume, and expiratory reserve volume. The vital capacity is total lung capacity minus residual volume.

Hence, the correct answer is option (D).

Additional information:
1.There are four types of lung volumes. These are tidal volume, residual volume, inspiratory reserve volume, and expiratory reserve volume.
2.There are four types of lung capacities depending on the volume of gas present in the lungs. These are total lung capacity, vital capacity, inspiratory capacity, and function residual capacity.
3.The inspiratory capacity can be defined as the maximum volume of air that can be inhaled. The inspiratory capacity is the sum of inspiratory reserve volume and tidal volume.
4.The function residual volume can be defined as the amount of air left in the lungs after exhalation. It is the sum of the residual volume and expiratory reserve volume.

Note: Residual volume can be defined as the volume of air present inside the lungs after maximum exhalation. On average, the amount of residual volume in the adult is 1200 mL.