Tidal volume is defined as the amount of air inhaled or exhaled in one breath. Which option correctly names tidal volume?

• A. Residual Volume
• B. Tidal Volume
• C. Dead Space
• D. Inspiratory Reserve Volume

Answer: (B)

Tidal volume refers to the amount of air that moves in or out with a normal breath during resting breathing. This is the standard, regular ventilation per cycle, roughly about 500 milliliters in a typical adult. The other terms describe different lung volumes: residual volume is the air left in the lungs after a full exhale and cannot be expelled; dead space is air in the conducting airways that does not participate in gas exchange; inspiratory reserve volume is the extra air you can inhale beyond the usual tidal volume with a deep inhalation. So, the term that matches the definition of the amount of air inhaled or exhaled in one normal breath is tidal volume.