Final answer:
Tidal volume is the amount of air inspired and expired during normal breathing, and it is approximately 500 ml.
Step-by-step explanation:
Tidal volume (TV) measures the amount of air inspired and expired during normal breathing. It is approximately 500 ml, which is about the size of a typical water bottle. Tidal volume is one of the respiratory volumes that help describe lung function, along with inspiratory reserve volume, expiratory reserve volume, and residual volume.