Define "tidal volume."

Tidal volume refers to the amount of air that is inhaled or exhaled during normal, quiet breathing. This measurement is important because it reflects the volume of air exchanged during a single respiratory cycle, providing insight into a person's respiratory function and efficiency. Normal tidal volume is typically around 500 milliliters in a healthy adult.

The other definitions provided do not accurately capture the essence of tidal volume. The total capacity of the lungs encompasses multiple volumes, including tidal volume, but is not limited to just the air exchanged during normal breaths. The volume of air remaining after exhalation relates to residual volume, which is specifically related to how much air remains in the lungs to keep the alveoli inflated, rather than the air exchanged in normal breathing. The maximum amount of air a person can breathe in pertains to inspiratory capacity or total lung capacity rather than tidal volume, which focuses solely on the air exchanged with each breath at rest.