Question

What are the indicatory for obstructive and restrictive pulmonary diseases on a pulmonary function test?

a) obstructive: a lower expired volume; restrictive: expires volume more slowly
b) obstructive: expires volume more slowly; restrictive: a lower expired volume
c) obstructive and restrictive: both expire volume more slowly
d) obstructive and restrictive: both expire a smaller volume

Answer 1

Obstructive lung diseases show a low FEV1/FVC ratio due to airway obstruction, causing slow exhalation, while restrictive lung diseases have a normal or high FEV1/FVC ratio with a reduced FVC due to stiff and non-compliant lung tissue.

Step-by-step explanation:

The indicators for obstructive and restrictive pulmonary diseases on a pulmonary function test are characterized by different patterns in the forced expiratory volume (FEV1) and forced vital capacity (FVC) measurements. In obstructive lung disease, such as asthma and emphysema, there is a lower FEV1/FVC ratio (less than 69 percent), indicating resistance and slow exhalation due to airway obstruction. Conversely, in restrictive lung disease, examples of which include respiratory distress syndrome and pulmonary fibrosis, the FEV1/FVC ratio is typically normal or high (88 to 90 percent), but the overall FVC is reduced, resulting from stiff or fibrotic lung tissue that cannot properly expand.