Question

Functional residual volume is?

• A. After normal inspiration
• B. After normal expiration
• C. After forceful expiration
• D. After forceful inspiration

Answer 1

The Correct Option is A

Functional Residual Volume (FRV) refers to the volume of air remaining in the lungs after a normal, passive expiration. It is essentially the sum of the expiratory reserve volume (ERV) and the residual volume (RV). Understanding these components is crucial to comprehending the concept of FRV.
Here's the breakdown of this concept:

• Expiration: When a person breathes out normally, not all air is expelled from the lungs. The air that remains in the lungs post-normal expiration forms part of the functional residual capacity (FRC).
• Functional Residual Volume Calculation: FRC = ERV + RV, where Expiratory Reserve Volume (ERV) is the additional air that can be expired after a normal expiration, and Residual Volume (RV) is the air remaining in the lungs even after forceful expiration.

Considering the given options, the correct context for the functional residual volume is after normal expiration, thereby ensuring the lungs retain air to prevent collapse and maintain gas exchange between breaths.