The amount of air that enters the lungs in a single inhalation or leaves the lungs in a single exhalation of quiet breathing.
Inspiratory reserve volume (IRV)
the air that can be forcibly inhaled after a normal respiration has taken place.
Expiratory reserve volume (ERV)
The amount of air that can be forcibly exhaled after a normal quiet respiration.
Residual Volume (RV)
The air remaining in the lungs after a forced exhalation; about 1500 cc in the adult.
Functional residual capacity (FRC)
The air that remains in the lungs after a normal exhalation has taken place.
Vital Capacity (VC)
The total volume of air thatt can be exhaled after a maximum inhalation. This amount will be equal to the sum of TV, IRV, and ERV.