Final answer:
The term 'tidal volume' describes the amount of air inhaled or exhaled during a normal breath. It is distinct from 'residual volume,' which is the air remaining after a maximal exhalation that prevents the alveoli from collapsing.
Step-by-step explanation:
The term used to describe the amount of air in a normal inhalation or exhalation is tidal volume. Tidal volume (TV) refers to the volume of air that is inspired and expired during a normal, quiet breath, which is approximately 500 milliliters.
The residual volume, on the other hand, is the air that remains in the lungs after a maximal exhalation to prevent the alveoli from collapsing. This ensures that the lungs do not empty completely, allowing easier breathing and avoiding large fluctuations in respiratory gases like oxygen and carbon dioxide.