Normal respiratory compliance is ?
a) 200 ml/cm water
b) 50 ml/cm water
c) 100 ml/cm water
d) 150 ml/cm water
Correct Answer - A
Ans. is ‘a’ i.e., 200 ml/cm water
The lungs and thoracic cage are both elastic structures. Hence they
display a constant relationship between distending pressure and
change in volume.
The change in volume per unit change in pressure is called
“compliance”.
The total compliance of both lungs together in the normal adult
human being is about 0.2 L/cm water.
That is, every time the transpulmonary pressure increases by 1
centimeter of water, the lung volume will expand 0.2 L (200 ml).
Compliance is a measure of distensibility.