The Total solution for NCERT class 6-12
(a) IRV and ERV
IRV (Inspiratory reserve volume)
ERV (Expiratory reserve volume)
It is the volume of air that a person can additionally inspire through a compelled inspiration
It is the volume of air that a person can expire through an expelled expiration
For a healthy individual, the IRV is approximately 2500ml – 3000ml
For a healthy individual, the ERV is approximately 1000ml to 1100ml
(b) Inspiratorycapacity and Expiratory capacity
Inspiratory capacity (IC)
Expiratory capacity (EC)
Inspiratory capacity is the volume of air that can be inhaled post a normal expiration
Expiratory capacity is the volume of air that can be exhaled post a normal inspiration
It is given by the sum of tidal volume and the inspiratory reserve volume
i.e, IC = TV + IRV
It is given by the tidal volume and the expiratory reserve volume
i.e., EC = TV + ERV
(c) Vital capacity andTotal lung capacity
Vital capacity (VC)
Total lung capacity (TLC)
After a maximum inspiration, it is the maximum volume of air that can be exhaled. It includes IC and ERV.
After maximum inspiration, it is the volume of air in the lungs. It includes ERV, IC and residual volume
The vital capacity in the lungs of humans is about 4000ml
The total lung capacity in the lungs of humans is nearly 5000ml to 6000ml