What term describes the amount of air entering the lungs in a single breath?

The correct term that describes the amount of air entering the lungs in a single breath is tidal volume. Tidal volume represents the volume of air inhaled or exhaled during normal breathing at rest, making it a fundamental measure in respiratory physiology. This measurement is crucial for understanding lung function and is commonly used in pulmonary assessments.

Inspiratory reserve volume refers to the additional amount of air that can be inhaled with a deep breath after a normal inhalation, while expiratory reserve volume is the additional amount of air that can be forcibly exhaled after a normal exhalation. Vital capacity, on the other hand, is the total volume of air that can be exhaled after a maximal inhalation and comprises tidal volume, inspiratory reserve volume, and expiratory reserve volume. Each of these terms describes different aspects of lung capacity and breathing but does not define the volume of air involved in a typical, relaxed breath like tidal volume does.