Which of the following pulmonary function values characterize an obstructive lung defect?
I.The forced vital capacity (FVC)may remain normal.
II.The forced expiratory volume in 1 second (FEV₁)is decreased.
III.The ratio of residual volume to total lung capacity (RV/TLC)may be normal.
IV.The FEV₁ is decreased.

Question

Quizplus · Accepted Answer

On the basis of spirometry,an obstructive lung disorder is characterized as follows:
•FVC normal or decreased
•FEV₁ decreased
•FEV₁/FVC decreased
•TLC normal or increased
•RV increased
•RV/TLC increased
Table 5-2 in the textbook compares obstructive and restrictive lung diseases in terms of these spirometric measurements.

Which of the Following Pulmonary Function Values Characterize an Obstructive