What does tidal volume measure?

Tidal volume specifically refers to the amount of air that is inhaled or exhaled during a single breath at rest. This measurement is essential for understanding lung function and respiratory efficiency, as it helps assess how much air is exchanged during normal breathing cycles.

In contrast, the other options deal with different physiological metrics. The total air moved through the lungs per minute pertains to minute ventilation, which is the product of tidal volume and respiratory rate. The volume of blood pumped per minute refers to cardiac output, which is unrelated to breathing. Finally, the amount of oxygen extracted by muscles relates to metabolic processes rather than the mechanical aspects of respiration. Thus, recognizing that tidal volume is solely focused on the volume of air per breath clarifies why it is specifically measured in this context.