To Compute Inspiratory Reserve Volume (IRV), One Would Need to Know

Question

To compute inspiratory reserve volume (IRV), one would need to know .
A) tidal volume, vital capacity, and expiratory reserve volume
B) vital capacity, and expiratory reserve volume
C) tidal volume and vital capacity

Accepted Answer

Inspiratory Reserve Volume (IRV) is calculated by subtracting the sum of Tidal Volume (TV) and Expiratory Reserve Volume (ERV) from the Vital Capacity (VC). This is because IRV represents the additional air that can be forcibly inhaled after the inhalation of a normal tidal volume, which requires knowing the total lung capacity available (VC), the amount used during normal breathing (TV), and the extra amount that can be exhaled beyond normal (ERV).