In a previous study it was found that the elastic
properties of lungs appeared to be unaffected by
age in healthy adults 17 to 39 years old (1). The
slope of the static volume-pressure curve of lungs
in the resting tidal range of breathing was used as
a measure of pulmonary compliance. The present
study extends observations to adults 50 years and
older. To obtain a more complete description of
the elastic behavior of lungs, static transpulmonary
pressure has been related to the total volume of gas
in the lungs, and the range of volume change has
been extended from that of tidal volume to inspiratory
capacity. In addition, measurement has
also been made of pulmonary compliance at various
rates of breathing, and of pulmonary flow resistance.
Finally, these data have been compared
with findings in young adults.