The work of breathing normally requires about 3% of total energy expenditure; this increases under all of the following situations except when
A)elastic recoil decreases
B)resistance increases
C)the partial pressure of oxygen increases in the air
D)ventilation increases
E)compliance decreases

Question

Quizplus · Accepted Answer

The partial pressure of oxygen in the air does not directly affect the work of breathing. The other options listed all increase the work of breathing. Elastic recoil and compliance both affect the ease with which the lungs can expand and contract, with decreased elastic recoil and compliance resulting in increased work. Resistance and ventilation both affect the amount of effort required to move air in and out of the lungs.

The Work of Breathing Normally Requires About 3% of Total