2025 PULMONARY FUNCTION TESTS
PFT EXAM QUESTIONS AND CORRECT
ANSWERS | COMPLETE ANSWERS A+
GRADE
Reasons for decreased FVC Correct Answer Surgical
procedure on lung; areas of collapse; conditions making
the lungs less expandable (fibrosis, CHF, thickened
pleura); obstructive lung disease; problems with the
pleural cavity (enlarged heart, fluid in pleura, tumor);
restriction of chest wall; inflation/deflation requires all
respiratory and accessory breathing muscles.
Reasons for decreased FEV1 Correct Answer Obstructive
defects; emphysema, chronic bronchitis, asthma.
What does it mean if the FVC or FEV1 are reduced in the
flow-volume loop? Correct Answer There is either
obstruction or restriction affecting the breathing.
Diffusing Capacity (aka Transfer Test) Correct Answer
The measurement of the transfer of a gas (CO) across the
alveolar-capillary membrane.
In a normal functioning lung, the primary limiting factor of
carbon monoxide is the status of the alveolar-capillary
membrane.
, What does diffusing capacity determine? Correct Answer
1. The lungs' ability to transfer gas (oxygen and carbon
dioxide).
2. The degree of abnormal alveolar-capillary involvement
(emphysema vs asthma or chronic bronchitis).
Factors that affect diffusing capacity results Correct
Answer 1. Ventilation: affects amount of CO.
2. Perfusion: amount of blood in the lungs.
3. How well ventilation and perfusion match.
4. Integrity of the alveolar-capillary interface.
5. Hemoglobin
Causes for REDUCTION of diffusion capacity Correct
Answer 1. Emphysema
2. Pulmonary fibrosis
3. Loss of parenchyma, space occupying lesions (tumor),
pulmonary edema.
4. Obesity
5. Extreme exercise: decreased capillary transit time.
Causes for INCREASED diffusion capacity Correct
Answer 1. Polycythemia
2. Pulmonary hemorrhage
3. Mild-moderate exercise
4. Asthmatic during airflow limitation (increase capillary
blood volume)
T/F: Pulmonary Function Tests are diagnostic tests.
Correct Answer False. They are physiologic tests.
PFT EXAM QUESTIONS AND CORRECT
ANSWERS | COMPLETE ANSWERS A+
GRADE
Reasons for decreased FVC Correct Answer Surgical
procedure on lung; areas of collapse; conditions making
the lungs less expandable (fibrosis, CHF, thickened
pleura); obstructive lung disease; problems with the
pleural cavity (enlarged heart, fluid in pleura, tumor);
restriction of chest wall; inflation/deflation requires all
respiratory and accessory breathing muscles.
Reasons for decreased FEV1 Correct Answer Obstructive
defects; emphysema, chronic bronchitis, asthma.
What does it mean if the FVC or FEV1 are reduced in the
flow-volume loop? Correct Answer There is either
obstruction or restriction affecting the breathing.
Diffusing Capacity (aka Transfer Test) Correct Answer
The measurement of the transfer of a gas (CO) across the
alveolar-capillary membrane.
In a normal functioning lung, the primary limiting factor of
carbon monoxide is the status of the alveolar-capillary
membrane.
, What does diffusing capacity determine? Correct Answer
1. The lungs' ability to transfer gas (oxygen and carbon
dioxide).
2. The degree of abnormal alveolar-capillary involvement
(emphysema vs asthma or chronic bronchitis).
Factors that affect diffusing capacity results Correct
Answer 1. Ventilation: affects amount of CO.
2. Perfusion: amount of blood in the lungs.
3. How well ventilation and perfusion match.
4. Integrity of the alveolar-capillary interface.
5. Hemoglobin
Causes for REDUCTION of diffusion capacity Correct
Answer 1. Emphysema
2. Pulmonary fibrosis
3. Loss of parenchyma, space occupying lesions (tumor),
pulmonary edema.
4. Obesity
5. Extreme exercise: decreased capillary transit time.
Causes for INCREASED diffusion capacity Correct
Answer 1. Polycythemia
2. Pulmonary hemorrhage
3. Mild-moderate exercise
4. Asthmatic during airflow limitation (increase capillary
blood volume)
T/F: Pulmonary Function Tests are diagnostic tests.
Correct Answer False. They are physiologic tests.
