CRE Respiratory System Anatomy & Physiology 2 — Questions and Answers
Question 1: Which cells lining the bronchial tree produce mucus that traps inhaled particles?
- Type I pneumocytes
- Goblet cells (Correct answer)
- Clara cells
- Brush cells
Correct answer: Goblet cells
Goblet cells are mucus-secreting epithelial cells found throughout the bronchial tree that help trap and remove inhaled debris.
Question 2: The functional residual capacity (FRC) is the sum of which two lung volumes?
- Tidal volume + inspiratory reserve volume
- Expiratory reserve volume + residual volume (Correct answer)
- Vital capacity + residual volume
- Inspiratory capacity + expiratory reserve volume
Correct answer: Expiratory reserve volume + residual volume
FRC equals expiratory reserve volume plus residual volume, representing the gas remaining in the lungs after a normal passive exhalation.
Question 3: Surfactant is produced primarily by which pulmonary cell type?
- Type I pneumocytes
- Alveolar macrophages
- Type II pneumocytes (Correct answer)
- Endothelial cells
Correct answer: Type II pneumocytes
Type II pneumocytes synthesize and secrete surfactant, a phospholipid mixture that reduces alveolar surface tension and prevents collapse.
Question 4: During inspiration, intrapleural pressure typically changes from approximately −5 cmH₂O to:
- −8 cmH₂O (Correct answer)
- +2 cmH₂O
- 0 cmH₂O
- −12 cmH₂O
Correct answer: −8 cmH₂O
During a normal tidal breath, intrapleural pressure drops from about −5 to −8 cmH₂O, creating the pressure gradient that drives airflow into the lungs.
Question 5: Which muscle is the PRIMARY muscle of inspiration during quiet breathing?
- External intercostals
- Sternocleidomastoid
- Diaphragm (Correct answer)
- Scalenes
Correct answer: Diaphragm
The diaphragm accounts for approximately 70–80% of the work of quiet inspiration by contracting and descending to increase thoracic volume.
Question 6: The angle of Louis (sternal angle) corresponds to which anatomical level, used to identify the carina?
- T4–T5 intervertebral disc (Correct answer)
- T1–T2 intervertebral disc
- T8 vertebral body
- C7 vertebral body
Correct answer: T4–T5 intervertebral disc
The sternal angle (angle of Louis) lies at the T4–T5 level and marks where the trachea bifurcates into the main stem bronchi at the carina.
Question 7: What is the approximate anatomical dead space in a healthy 70 kg adult?
- 50 mL
- 150 mL (Correct answer)
- 350 mL
- 500 mL
Correct answer: 150 mL
Anatomical dead space is roughly 1 mL per pound of ideal body weight, approximating 150 mL in a 70 kg adult, representing conducting airways that don't participate in gas exchange.
CRE Respiratory System Anatomy & Physiology 2
Which cells lining the bronchial tree produce mucus that traps inhaled particles?