Figure 22. 16 Respiratory volume and Capacities.
Tidal Volume ( TV)
Normal breathing volume approximately 500 ml.
Inspiratory reserve volume ( IRV)
After a normal inhalation if you force in air ( suck in air) that is the inspiratory reserve volume which is about 3100 ml.
Expiratory reserve volume ( ERV)
is the air you blow out of the lungs after a deep breath ( Inspiratory volume) which is about 1200 ml.
Residual Volume ( RV)
Is air remaining in the lungs, its about 1200 ml. helps keep the alveoli open and prevents lung collapse.
What is capacity?
is combining two or more volumes.
Inspiratory capacity ( IC)
is the tidal volume ( TV) plus inspiratory reserve volume ( IRV) which equals 3600 ml. Total amount of air that can be inspired after a tidal expiration.
Functional residual capacity ( FRC)
Amount of air remaining in lungs after a tidal expiration. Expiratory reserve volume ( ERV) plus residual volume (RV) which equals 2400 ml.
Vital Capacity ( VC)
The total amount of exchangeable air, it's what you have control over. Tidal volume plus Inspiratory reserve volume plus Expiratory reserve volume. TV t IRV t ERV which equals 4800 ml.
Total lung capacity ( TLC)
The sum of all lung volumes, normally about 6000 ml.
Alveolar ventilation rate ( AVR)
Measures the flow of fresh gases into or out of the alveoli during a particular time.
Forced vital capacity ( FVC)
Air forcibly expelled after taking a deep breath.
Forced expiratory volume ( FEV)
Amount of gas expelled during specific time intervals of the forced vital capacity ( FVC).