Which volume is calculated as the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume?

The correct answer is vital capacity, which is understood as the maximum amount of air that can be expelled from the lungs after a maximum inhalation. It encompasses three key lung volumes: tidal volume, which is the amount of air inhaled or exhaled during normal breathing; inspiratory reserve volume, which is the additional air that can be inhaled after a normal inhalation; and expiratory reserve volume, which is the additional air that can be exhaled after a normal exhalation.

By summing these three components, vital capacity provides a comprehensive measure of lung function and is crucial for assessing respiratory health. This measurement can give insights into the effectiveness of the respiratory system and its ability to accommodate increased demand for airflow during activities such as exercise.

Other options like residual volume refer specifically to the air that remains in the lungs after a full exhale, while functional residual capacity involves the volume of air remaining in the lungs after normal exhalation. Inspiratory capacity focuses solely on the maximum amount of air that can be inhaled after a normal exhalation. These measures do not encompass the entire range of volumes included in vital capacity, which is specifically relevant in the context of maximum air exchange in the lungs.