2026/2027 Herzing University
Q1. Which process is primarily responsible for movement of oxygen
from the alveoli into pulmonary capillary blood?
A) Active transport
B) Diffusion down a partial-pressure gradient
C) Osmosis
D) Facilitated transport by sodium channels
Correct Answer: B) Diffusion down a partial-pressure gradient
Rationale: Oxygen moves passively across the alveolar-capillary membrane
from an area of higher partial pressure to lower partial pressure.
Q2. Which factor most directly determines alveolar ventilation?
A) Total lung capacity multiplied by respiratory rate
B) Tidal volume minus dead-space volume, multiplied by respiratory rate
C) Residual volume divided by respiratory rate
D) Inspiratory reserve volume multiplied by heart rate
Correct Answer: B) Tidal volume minus dead-space volume, multiplied by
respiratory rate
Rationale: Alveolar ventilation represents the volume of fresh gas reaching
functioning alveoli each minute.
Q3. Which condition decreases lung compliance?
A) Pulmonary fibrosis
B) Emphysema
C) Normal aging only
D) Chronic bronchitis without parenchymal change
Correct Answer: A) Pulmonary fibrosis
Rationale: Fibrotic tissue makes the lungs stiff, increasing the pressure
required to expand them.
Q4. Which change is characteristic of emphysema?
A) Increased elastic recoil
B) Increased alveolar surface area
C) Loss of elastic recoil and increased lung compliance
D) Reduced total lung capacity in every patient
Correct Answer: C) Loss of elastic recoil and increased lung compliance
Rationale: Destruction of alveolar walls reduces elastic recoil, allowing
excessive lung expansion while impairing expiratory emptying.
, Q5. Surfactant primarily functions to:
A) Reduce alveolar surface tension and prevent collapse
B) Increase pulmonary vascular resistance
C) Stimulate mucus production
D) Increase airway smooth-muscle contraction
Correct Answer: A) Reduce alveolar surface tension and prevent collapse
Rationale: Surfactant stabilizes alveoli by lowering surface tension,
especially at low lung volumes.
Q6. Which cells produce pulmonary surfactant?
A) Type II alveolar cells
B) Type I alveolar cells
C) Alveolar macrophages
D) Bronchial smooth-muscle cells
Correct Answer: A) Type II alveolar cells
Rationale: Type II pneumocytes synthesize and secrete surfactant and can
also participate in alveolar epithelial repair.
Q7. A ventilation-perfusion ratio approaching zero indicates:
A) Excess ventilation relative to blood flow
B) Normal gas exchange
C) Complete absence of blood flow
D) Perfusion without adequate ventilation, producing a shunt-like state
Correct Answer: D) Perfusion without adequate ventilation, producing a
shunt-like state
Rationale: Blood passing through poorly ventilated alveoli cannot become
adequately oxygenated.
Q8. Which situation most closely represents alveolar dead space?
A) Perfusion without ventilation
B) Normal ventilation and perfusion
C) Ventilation without adequate perfusion
D) Diffusion without ventilation
Correct Answer: C) Ventilation without adequate perfusion
Rationale: Dead space occurs when alveoli are ventilated but receive little
or no pulmonary blood flow.
Q9. A pulmonary embolus primarily causes hypoxemia by producing:
A) A pure right-to-left anatomic shunt
B) Reduced surfactant production only
C) Ventilation-perfusion mismatch with increased dead space
D) Increased alveolar diffusion capacity