Question

The compliance of the lungs and chest wall is 

A. Expressed as volume change per unit change in pressure.

B. Minimal during quiet breathing. 

C. Increased by the surface tension of the fluid lining the alveoli. 

D. Increased by surfactant. 

E. Changed by parallel displacement of the line relating lung volume to distending pressure.

Answer 1

A. True The normal value is about 0.1 litre/cm H₂O (1 litre/kPa). 

B. False It is maximal over this range of chest movement. 

C. False The surface tension of alveolar fluid decreases compliance. 

D. True This decreases the surface tension. 

E. False The slope of this line indicates compliance and is unchanged by a parallel shift.