State the volume of air remaining in the lungs after a normal breathing.
The volume of air remaining in the lungs after a normal expiration is called Functional Residual Capacity (FRC). It includes Expiratory Reserve Volume (ERV) and Residual Volume (RV). The approximate volume is 2100 mL to 2300 mL (ERV: 1000-1100 mL + RV: 1100-1200 mL).
Explanation
The question asks about the air remaining in lungs after normal breathing (expiration). According to the textbook context, Functional Residual Capacity (FRC) is defined as 'Volume of air that will remain in the lungs after a normal expiration. This includes ERV+RV.' The ERV averages 1000-1100 mL and RV averages 1100-1200 mL, giving a total FRC of approximately 2100-2300 mL. Note: Residual Volume (RV) alone is the air remaining after a forcible expiration, not normal breathing, so FRC is the correct answer for normal expiration.