Class 11 NEET Biology Breathing and Exchange of Gases

(a) : Residual volume is the amount of air that remains in the lungs after forcible expiration. It is about 1500ml. It enables the lungs to continue exchange of gases even after maximum exhalation or holding the breath. Inspiratory reserve volume is the extra amount of air which can be inhaled forcibly after a normal inspiration. It is about 2000 to 2500ml. Vital capacity is the amount of air which one can inhale and also exhale with maximum effort. It is about 3.5−4.5 litres. Tidal volume (500ml) is the volume of air normally inspired or expired in one breath without any effort.