Question 13
Distinguish between
(a) IRV and ERV
(b) Inspiratory capacity and Expiratory capacity
(c) Vital capacity and Total lung capacity
(a)
Inspiratory reserve volume (IRV) | Expiratory reserve volume (ERV) |
1. It is the maximum volume of air that can be inhaled after a normal inspiration. 2. It is about 2500 – 3500 mL in the human lungs. | 1. It is the maximum volume of air that can be exhaled after a normal expiration. 2. It is about 1000 – 1500 mL in the human lungs. |
(b)
Inspiratory capacity (IC) | Expiratory capacity (EC) |
1. It is the volume of air that can be inhaled after a normal expiration. 2. It includes tidal volume and inspiratory reserve volume. IC = TV + IRV | 1. It is the volume of air that can be exhaled after a normal inspiration. 2. It includes tidal volume and expiratory reserve volume. EC = TV + ERV |
(c)
Vital capacity (VC) | Total lung capacity (TLC) |
1. It is the maximum volume of air that can be exhaled after a maximum inspiration. It includes IC and ERV. 2. It is about 4000 mL in the human lungs. | 1. It is the volume of air in the lungs after maximum inspiration. It includes IC, ERV, and residual volume. 2. It is about 5000 – 6000 mL in the human lungs. |
