Which volume represents the amount of air that can be forcefully exhaled after normal exhalation?

The amount of air that can be forcefully exhaled after a normal exhalation is known as expiratory reserve volume. This volume reflects the additional air that can be exhaled beyond the tidal volume (the amount of air inhaled or exhaled during normal breathing) when one takes a deep breath out. After normal tidal expiration, there remains a reserve of air in the lungs that can be expelled with effort, which is what expiratory reserve volume measures.

Understanding this concept is fundamental in the study of respiratory physiology, as it provides insights into lung function and the mechanics of breathing. This volume is particularly important for evaluating conditions that affect lung capacity and can aid in the diagnosis of various pulmonary disorders.