The term 'Tidal volume' refers to the volume of air exchanged with each breath and it is typically measured in what unit?

• A. Liters
• B. Milliliters
• C. Cubic centimeters
• D. Deciliters

Answer: (B)

Tidal volume is a critical parameter in respiratory physiology that quantifies the volume of air that is inhaled or exhaled during a normal breath. This measurement is typically expressed in milliliters, as it allows for sufficient granularity to capture the relatively small volumes exchanged in the lungs with each breath.

Using milliliters is advantageous in clinical and research settings, as tidal volume values generally range from about 300 to 500 mL in resting adults, making milliliters the most practical unit for capturing these volumes. While liters, cubic centimeters, and deciliters are also units of volume, they are not as commonly used in the context of measuring tidal volume, especially considering the usual range of values involved. Milliliters provide a more precise measurement suitable for the small volumes relevant in human respiratory mechanics.