NBRC Cardiopulmonary Anatomy and Physiology 2 — Questions and Answers
Question 1: The functional residual capacity (FRC) is the sum of which two lung volumes?
- Tidal volume and inspiratory reserve volume
- Expiratory reserve volume and residual volume (Correct answer)
- Inspiratory capacity and residual volume
- Vital capacity and residual volume
Correct answer: Expiratory reserve volume and residual volume
FRC equals expiratory reserve volume (ERV) plus residual volume (RV), representing the lung volume remaining after a passive exhalation.
Question 2: Hypoxic pulmonary vasoconstriction (HPV) serves to:
- Increase blood flow to poorly ventilated areas
- Divert blood away from poorly ventilated alveoli (Correct answer)
- Decrease pulmonary vascular resistance globally
- Raise alveolar PO2 in well-ventilated regions
Correct answer: Divert blood away from poorly ventilated alveoli
HPV redirects pulmonary blood flow away from hypoxic lung segments to better-ventilated areas, optimizing V/Q matching.
Question 3: Which of the following best describes anatomical dead space?
- Alveoli that are ventilated but not perfused
- Conducting airways that do not participate in gas exchange (Correct answer)
- The volume of gas remaining after maximal exhalation
- Lung tissue destroyed by emphysema
Correct answer: Conducting airways that do not participate in gas exchange
Anatomical dead space comprises the conducting airways (nose, trachea, bronchi) where no gas exchange occurs, roughly 150 mL in adults.
Question 4: Surfactant is produced by which cell type?
- Type I pneumocytes
- Type II pneumocytes (Correct answer)
- Goblet cells
- Clara cells
Correct answer: Type II pneumocytes
Type II pneumocytes synthesize and secrete pulmonary surfactant, which reduces alveolar surface tension and prevents alveolar collapse.
Question 5: A patient has a V/Q ratio of zero. This indicates:
- Normal gas exchange
- Dead space ventilation
- Intrapulmonary shunt (Correct answer)
- Diffusion impairment
Correct answer: Intrapulmonary shunt
A V/Q ratio of zero means there is perfusion but no ventilation, which constitutes a true intrapulmonary shunt.
Question 6: The normal arterial pH range is:
- 7.20–7.30
- 7.30–7.35
- 7.35–7.45 (Correct answer)
- 7.45–7.55
Correct answer: 7.35–7.45
Arterial blood pH is normally maintained between 7.35 and 7.45 by respiratory and renal buffering mechanisms.
NBRC Cardiopulmonary Anatomy and Physiology 2
The functional residual capacity (FRC) is the sum of which two lung volumes?