BIOL 252 Anatomy & Physiology II Module 5 Exam
Respiratory System Complete Q&A Guide
200 Practice Questions with Verified Answers and
Explanations
1. Which of the following structures is considered part of the "Respiratory Zone" where actual gas
exchange occurs?
A. Terminal bronchioles
B. Trachea
C. Alveolar ducts
D. Primary bronchi
Answer: C. Alveolar ducts
Explanation: The conducting zone moves air, but the respiratory zone begins where alveoli appear,
specifically starting at the respiratory bronchioles and extending to the alveolar ducts and sacs.
2. According to Boyle's Law, what must happen to the intrapulmonary pressure in order for inhalation to
occur?
A. It must rise above atmospheric pressure
B. It must fall below atmospheric pressure
C. It must equal the intrapleural pressure
D. It must remain constant while volume decreases
,Answer: B. It must fall below atmospheric pressure
Explanation: Boyle's Law states that pressure and volume are inversely related. When the thoracic cavity
volume increases, intrapulmonary pressure drops (becomes negative) relative to the outside air, sucking
air into the lungs.
3. Which cell type is responsible for producing pulmonary surfactant?
A. Type I alveolar cells
B. Type II alveolar cells
C. Alveolar macrophages
D. Goblet cells
Answer: B. Type II alveolar cells
Explanation: Type II cells (great alveolar cells) secrete surfactant, which breaks the surface tension of
water inside the alveoli, preventing the lungs from collapsing during expiration.
4. Most of the carbon dioxide (CO₂) in the blood is transported in which form?
A. Dissolved directly in the plasma
B. Bound to the heme group of hemoglobin
C. As bicarbonate ions (HCO₃⁻)
D. As carbonic anhydrase
Answer: C. As bicarbonate ions (HCO₃⁻)
,Explanation: Approximately 70% of CO₂ is transported as bicarbonate in the plasma after being
converted by carbonic anhydrase within red blood cells.
5. The principal muscle(s) involved in inspiration is (are):
A. The diaphragm
B. Rectus abdominis
C. The scalene muscles
D. Sternocleidomastoids
Answer: A. The diaphragm
Explanation: The diaphragm is the main muscle of inspiration; contraction forces the abdominal
contents down, creating a relative vacuum in the thorax which "sucks" air into the lungs.
6. Lung compliance:
A. Is reduced as lung volume increases
B. Is reduced in emphysema
C. Is increased in lung fibrosis
D. Is the change in pleural pressure per unit change in lung volume
Answer: A. Is reduced as lung volume increases
, Explanation: Lung compliance is the change in lung volume brought about by a unit change in
transpulmonary (intrapleural) pressure. The fibrotic lung is less compliant; the emphysematous lung is
more compliant. In any lung, its capacity to stretch (expand) is reduced as volume increases.
7. In relation to airway resistance:
A. Overall airway resistance increases as lung volume increases
B. In health, at high lung volume, the greater part of airway resistance is situated in the central airways
C. Airway resistance is reduced in emphysema
D. Airway resistance is proportional to the cubed power of the radius
Answer: B. In health, at high lung volume, the greater part of airway resistance is situated in the central
airways
Explanation: Airway resistance in health resides principally in the central (large) airways at high lung
volume. As lung volume decreases, the site of greatest resistance moves peripherally to the smaller
airways. Airway resistance is proportional to r⁴ (not r³).
8. In relation to ventilation (V) and perfusion (Q):
A. The upper zones of the lungs are ventilated more than the lower zones
B. The upper zones of the lungs receive more perfusion than the lower zones
C. V/Q is greater in the lower zones
D. V/Q matching is essential to gas exchange
Answer: D. V/Q matching is essential to gas exchange
Respiratory System Complete Q&A Guide
200 Practice Questions with Verified Answers and
Explanations
1. Which of the following structures is considered part of the "Respiratory Zone" where actual gas
exchange occurs?
A. Terminal bronchioles
B. Trachea
C. Alveolar ducts
D. Primary bronchi
Answer: C. Alveolar ducts
Explanation: The conducting zone moves air, but the respiratory zone begins where alveoli appear,
specifically starting at the respiratory bronchioles and extending to the alveolar ducts and sacs.
2. According to Boyle's Law, what must happen to the intrapulmonary pressure in order for inhalation to
occur?
A. It must rise above atmospheric pressure
B. It must fall below atmospheric pressure
C. It must equal the intrapleural pressure
D. It must remain constant while volume decreases
,Answer: B. It must fall below atmospheric pressure
Explanation: Boyle's Law states that pressure and volume are inversely related. When the thoracic cavity
volume increases, intrapulmonary pressure drops (becomes negative) relative to the outside air, sucking
air into the lungs.
3. Which cell type is responsible for producing pulmonary surfactant?
A. Type I alveolar cells
B. Type II alveolar cells
C. Alveolar macrophages
D. Goblet cells
Answer: B. Type II alveolar cells
Explanation: Type II cells (great alveolar cells) secrete surfactant, which breaks the surface tension of
water inside the alveoli, preventing the lungs from collapsing during expiration.
4. Most of the carbon dioxide (CO₂) in the blood is transported in which form?
A. Dissolved directly in the plasma
B. Bound to the heme group of hemoglobin
C. As bicarbonate ions (HCO₃⁻)
D. As carbonic anhydrase
Answer: C. As bicarbonate ions (HCO₃⁻)
,Explanation: Approximately 70% of CO₂ is transported as bicarbonate in the plasma after being
converted by carbonic anhydrase within red blood cells.
5. The principal muscle(s) involved in inspiration is (are):
A. The diaphragm
B. Rectus abdominis
C. The scalene muscles
D. Sternocleidomastoids
Answer: A. The diaphragm
Explanation: The diaphragm is the main muscle of inspiration; contraction forces the abdominal
contents down, creating a relative vacuum in the thorax which "sucks" air into the lungs.
6. Lung compliance:
A. Is reduced as lung volume increases
B. Is reduced in emphysema
C. Is increased in lung fibrosis
D. Is the change in pleural pressure per unit change in lung volume
Answer: A. Is reduced as lung volume increases
, Explanation: Lung compliance is the change in lung volume brought about by a unit change in
transpulmonary (intrapleural) pressure. The fibrotic lung is less compliant; the emphysematous lung is
more compliant. In any lung, its capacity to stretch (expand) is reduced as volume increases.
7. In relation to airway resistance:
A. Overall airway resistance increases as lung volume increases
B. In health, at high lung volume, the greater part of airway resistance is situated in the central airways
C. Airway resistance is reduced in emphysema
D. Airway resistance is proportional to the cubed power of the radius
Answer: B. In health, at high lung volume, the greater part of airway resistance is situated in the central
airways
Explanation: Airway resistance in health resides principally in the central (large) airways at high lung
volume. As lung volume decreases, the site of greatest resistance moves peripherally to the smaller
airways. Airway resistance is proportional to r⁴ (not r³).
8. In relation to ventilation (V) and perfusion (Q):
A. The upper zones of the lungs are ventilated more than the lower zones
B. The upper zones of the lungs receive more perfusion than the lower zones
C. V/Q is greater in the lower zones
D. V/Q matching is essential to gas exchange
Answer: D. V/Q matching is essential to gas exchange
