Distinguish between
a) IRV and ERV
b) Inspiratory capacity and Expiratory capacity
c) Vital capacity and Total lung capacity.

Explanation

a) IRV and ERV:
IRV (Inspiratory Reserve Volume) : The maximum volume of air that can be inhaled during forced breathing, in addition to the tidal volume. This is about 2500 ml to 3000 ml.
ERV (Expiratory Reserve Volume) : The maximum volume of air that can be exhaled during forced breathing in addition to the tidal volume.. This is about 1000 ml to 1100 ml.
b) Inspiratory capacity and
Expiratory capacity :
Inspiratory capacity (IC) : The total volume of air, a person can inhale after normal expiration.. This includes tidal volume and inspiratory reserve volume. IV = TV + IRV It is about 3000 ml to 3500 ml. Expiratory capacity (EC) : The total volume of air, a person can expire after a .normal inspiration.. This includes tidal volume and expiratory reserve volume. EC = TV + ERV
c) Vital capacity and Total lung capacity :
Vital capacity (VC): The maximum volume of air a person can breathe in after .forced expiration.. This includes ERV, TV and IRV. (or) the maximum volume of air, a person can breathe out after forced inspiration. VC = TV + IRV + ERV
Total lung capacity (TLC): The total volume of air accommodated in the lungs at the end of forced inspiration.
This includes RV, ERV, TV and IRV
TLC = ERV + IRV + TV + RV (or)
TLC = Vital capacity + residual volume.