Tidal volume is the volume of air inspired or expired during normal breathing in relaxed or resting position. Its volume is about 500 mL.
Amount of Tidal Volume (TV) in an hour = Respiratory rate x TV x 60 min
= (12-16 breaths per minute) x 500mL x 60 = 6-8 L x 60
TV = 360 - 480 L
A — Alveolar cavity, B — Alveolar wall, C — Red blood cells, D — Basement substance.