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Pathophysiology NU 545 - Unit 5:
Pulmonary and Renal Systems
Questions With Verified Solutions And
Rationales
1. Which of the following is the primary function of the pulmonary system?
A. Regulation of blood glucose
B. Gas exchange and maintenance of acid-base balance
C. Production of red blood cells
D. Regulation of body temperature
Correct Answer: B
Rationale: The primary function of the pulmonary system is gas exchange
(oxygenation and ventilation) and maintenance of acid-base balance through
regulation of carbon dioxide levels .
2. Which structure is the primary site of gas exchange in the lungs?
A. Bronchi
B. Bronchioles
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C. Alveoli
D. Trachea
Correct Answer: C
Rationale: The alveoli are the primary site of gas exchange. Oxygen diffuses across
the alveolar-capillary membrane into the blood, and carbon dioxide diffuses from
the blood into the alveoli .
3. What is the definition of tidal volume (TV)?
A. The maximum amount of air that can be inhaled after a normal inhalation
B. The volume of air inhaled and exhaled during a normal breath
C. The maximum amount of air that can be exhaled after a maximum inhalation
D. The volume of air remaining in the lungs after a maximum exhalation
Correct Answer: B
Rationale: Tidal volume (TV) is the volume of air inhaled and exhaled during a
normal breath. It is approximately 500 mL in adults .
4. What is vital capacity (VC)?
A. The maximum amount of air that can be exhaled after a maximum inhalation
B. The volume of air inhaled and exhaled during a normal breath
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C. The volume of air remaining in the lungs after a maximum exhalation
D. The total volume of air in the lungs
Correct Answer: A
Rationale: Vital capacity (VC) is the maximum amount of air that can be exhaled
after a maximum inhalation. It is the sum of tidal volume, inspiratory reserve
volume, and expiratory reserve volume .
5. Which of the following is NOT a mechanical factor affecting ventilation?
A. Compliance
B. Airway resistance
C. Surface tension
D. Hemoglobin concentration
Correct Answer: D
Rationale: Hemoglobin concentration affects oxygen transport, not ventilation.
Mechanical factors affecting ventilation include compliance, airway resistance,
and surface tension .
6. What is the primary driving force for gas exchange in the lungs?
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A. Active transport
B. Diffusion down partial pressure gradients
C. Osmosis
D. Facilitated diffusion
Correct Answer: B
Rationale: Gas exchange occurs by diffusion down partial pressure gradients.
Oxygen moves from the alveoli (high PO2) into the blood (low PO2), and carbon
dioxide moves from the blood (high PCO2) into the alveoli (low PCO2) .
7. What is the primary cause of hypoxemia in a patient with chronic bronchitis?
A. Decreased oxygen diffusion capacity
B. Ventilation-perfusion (V/Q) mismatch
C. Decreased cardiac output
D. Anemia
Correct Answer: B
Rationale: Chronic bronchitis causes airflow obstruction and mucus plugging,
leading to V/Q mismatch. This is a common cause of hypoxemia in COPD .
8. What is the primary cause of hypoxemia in a patient with pulmonary edema?
Pathophysiology NU 545 - Unit 5:
Pulmonary and Renal Systems
Questions With Verified Solutions And
Rationales
1. Which of the following is the primary function of the pulmonary system?
A. Regulation of blood glucose
B. Gas exchange and maintenance of acid-base balance
C. Production of red blood cells
D. Regulation of body temperature
Correct Answer: B
Rationale: The primary function of the pulmonary system is gas exchange
(oxygenation and ventilation) and maintenance of acid-base balance through
regulation of carbon dioxide levels .
2. Which structure is the primary site of gas exchange in the lungs?
A. Bronchi
B. Bronchioles
,2|Page
C. Alveoli
D. Trachea
Correct Answer: C
Rationale: The alveoli are the primary site of gas exchange. Oxygen diffuses across
the alveolar-capillary membrane into the blood, and carbon dioxide diffuses from
the blood into the alveoli .
3. What is the definition of tidal volume (TV)?
A. The maximum amount of air that can be inhaled after a normal inhalation
B. The volume of air inhaled and exhaled during a normal breath
C. The maximum amount of air that can be exhaled after a maximum inhalation
D. The volume of air remaining in the lungs after a maximum exhalation
Correct Answer: B
Rationale: Tidal volume (TV) is the volume of air inhaled and exhaled during a
normal breath. It is approximately 500 mL in adults .
4. What is vital capacity (VC)?
A. The maximum amount of air that can be exhaled after a maximum inhalation
B. The volume of air inhaled and exhaled during a normal breath
,3|Page
C. The volume of air remaining in the lungs after a maximum exhalation
D. The total volume of air in the lungs
Correct Answer: A
Rationale: Vital capacity (VC) is the maximum amount of air that can be exhaled
after a maximum inhalation. It is the sum of tidal volume, inspiratory reserve
volume, and expiratory reserve volume .
5. Which of the following is NOT a mechanical factor affecting ventilation?
A. Compliance
B. Airway resistance
C. Surface tension
D. Hemoglobin concentration
Correct Answer: D
Rationale: Hemoglobin concentration affects oxygen transport, not ventilation.
Mechanical factors affecting ventilation include compliance, airway resistance,
and surface tension .
6. What is the primary driving force for gas exchange in the lungs?
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A. Active transport
B. Diffusion down partial pressure gradients
C. Osmosis
D. Facilitated diffusion
Correct Answer: B
Rationale: Gas exchange occurs by diffusion down partial pressure gradients.
Oxygen moves from the alveoli (high PO2) into the blood (low PO2), and carbon
dioxide moves from the blood (high PCO2) into the alveoli (low PCO2) .
7. What is the primary cause of hypoxemia in a patient with chronic bronchitis?
A. Decreased oxygen diffusion capacity
B. Ventilation-perfusion (V/Q) mismatch
C. Decreased cardiac output
D. Anemia
Correct Answer: B
Rationale: Chronic bronchitis causes airflow obstruction and mucus plugging,
leading to V/Q mismatch. This is a common cause of hypoxemia in COPD .
8. What is the primary cause of hypoxemia in a patient with pulmonary edema?
