State the volume of air remaining in the lungs after a normal breathing.
State the volume of air remaining in the lungs after a normal breathing.

Solution: The functional residual capacity can be used to express it (FRC). The volume of air that remains in the lungs following a normal expiration is referred to as the FRC. The expiratory reserve volume (ERV) and residual volume constitute the functional residual capacity (RV).

The expiratory reserve volume is the maximum amount of air that can be exhaled after a normal expiration, which is between 1000 and 1500 ml. The residual volume is the amount of air in the lungs following maximum expiration, which is approximately 1100ml to 1500ml.

Hence, Functional Residual Capacity (FRC) = Expiratory Reserve Volume (ERV) + Residual Volume (RV) ≅ 1500 + 1500 = 3000 ml

Thus, the functional residual capacity of the lungs in human beings is nearly 2500 ml to 3000 ml