Lung volumes
There are several different measures of lung volumes, some of which can be taken by Spirometry [1]. They are:
- Tidal Volume (TV)
The volume of air inspired and expired over the course of a normal breath. This is around 500 ml - Inspiratory Reserve Volume (IRV)
The volume of air that can be inspired over and above that of a normal (tidal volume) breath. This is around 3100 ml - Expiratory Reserve Volume (ERV)
The Volume of air that can be expired over and above that of a normal breath. This is around 1200 ml - Residual Volume (RV)
The volume of air that is left in the lungs after maximal expiration; that is after the expiratory reserve volume. It is around 1200 ml but cannot be measured by spirometry. - Inspiratory Capasity (IC)
The volume of maximal inspiration: IRV+TV - Functional residual capasity (FRC)
The volume of gas remaining in the lung after normal expiration: ERV+RV - Vital capasity (VC)
Volume of maximal inspiration and expiration: IRV+ERV+TV - Total lung capasity (TLC)
The volume of the lung after maximal inspiration sum of all four lung volumes, IC+FRC