Definition of each volume:
Tidal volume: volume that is moved into or out of the lungs in the course of breathing – when resting it is about 0,5 l.
Inspiratory/expiratory reserve volume: volume by which a breath can be increased maximally by choice. For the expiration it is 1,5 l, for the inspiration it is 2,5 l.
Residual volume: volume that stays in the lung permanently and that cannot be expired by choice. In a healthy adult it is 1,5 l.
Inspiratory capacity = tidal volume + inspiratory reserve volume
Functional residual capacity = expiratory reserve volume + residual volume (also the volume that remains in normal breathing in the lung)
Vital capacity = maximal volume that can be inspired after maximal expiration (inspiratory vital capacity)/maximal volume that can be expired after maximal inspiration (expiratory vital capacity).
Total lung capacity = volume in the lung after maximal inspiration
