Figure 1.
Pressure volume relationship of the passive respiratory system. Lower and upper boundaries of the elastic recoil pressure–volume relationship of the respiratory system in healthy subjects (---), in patients with narrowed airways (—), and in patients with loss of lung elastic recoil (·····). The loops represent tidal breathing at rest (—) and during exercise (·····).
Abbreviations: FRC, functional residual capacity; VC, vital capacity.