,BIOL331/BIOL 331 Pathophysiology Module 5
Exam | Portage Learning |Q&A | 26/27 Edition
(PDF)
1. Which of the following best defines ventilation?
A) The exchange of gases between the alveoli and the blood
B) The flow of gases into and out of the alveoli of the lungs
C) The transport of oxygen in the bloodstream
D) The process of cellular respiration
Correct Answer: The flow of gases into and out of the alveoli of the lungs
Rationale: Ventilation is the mechanical process of moving air into and out of the lungs, specifically the
alveoli. Diffusion is the exchange of gases between alveoli and blood. Transport of oxygen occurs via
hemoglobin, and cellular respiration occurs at the tissue level.
2. What is the term used to describe the ease or difficulty with which the lungs can be inflated?
A) Resistance
B) Compliance
C) Elasticity
D) Tidal volume
Correct Answer: Compliance
Rationale: Lung compliance reflects the distensibility of lung tissue—how easily the lungs can be
inflated. High compliance is seen in emphysema, while low compliance (stiff lungs) occurs in fibrosis or
pulmonary edema.
3. The diaphragm is innervated by which nerve roots?
A) T2–T4
,B) C3, C4, C5
C) L1–L3
D) S1–S2
Correct Answer: C3, C4, C5
Rationale: The phrenic nerve, originating from cervical nerve roots C3, C4, and C5, provides motor
innervation to the diaphragm. The mnemonic "C3, 4, 5 keeps the diaphragm alive" is commonly used to
remember this.
4. The breathing rate is determined by input from which receptors that monitor oxygen, carbon dioxide,
and pH levels in the blood?
A) Baroreceptors
B) Chemoreceptors
C) Stretch receptors
D) Nociceptors
Correct Answer: Chemoreceptors
Rationale: Chemoreceptors, both central (in the medulla) and peripheral (in carotid and aortic bodies),
sense changes in arterial oxygen, carbon dioxide, and pH. Their feedback modulates respiratory centers
to adjust ventilation and maintain homeostasis.
5. A reduction in blood O₂ levels is known as:
A) Hypoxia
B) Hypoxemia
C) Hypercapnia
D) Anoxia
Correct Answer: Hypoxemia
, Rationale: Hypoxemia specifically refers to decreased arterial oxygen tension (PaO₂), regardless of total
O₂ content or delivery. Hypoxia is a broader term for inadequate oxygen at the tissue level.
6. Which of the following statements about inspiration and expiration is TRUE?
A) Inspiration is passive, and expiration is active
B) Inspiration is active, and expiration is passive at rest
C) Both inspiration and expiration are active processes
D) Both inspiration and expiration are passive processes
Correct Answer: Inspiration is active, and expiration is passive at rest
Rationale: Inspiration requires contraction of the diaphragm and external intercostal muscles and is
therefore active. Expiration at rest is passive due to elastic recoil of the lungs. Expiratory muscles are
recruited only during forced expiration.
7. Even after forced expiration, a significant amount of air remains in the lungs. This is called:
A) Tidal volume
B) Vital capacity
C) Residual volume
D) Expiratory reserve volume
Correct Answer: Residual volume
Rationale: After maximal (forced) expiration, the residual volume (RV) remains in the lungs to prevent
collapse and maintain alveolar inflation. Tidal volume is the air moved during normal breathing, and vital
capacity is the maximum amount of air that can be exhaled after a maximal inhalation.
8. Both carbon dioxide and oxygen are able to bind with hemoglobin.
A) True
Exam | Portage Learning |Q&A | 26/27 Edition
(PDF)
1. Which of the following best defines ventilation?
A) The exchange of gases between the alveoli and the blood
B) The flow of gases into and out of the alveoli of the lungs
C) The transport of oxygen in the bloodstream
D) The process of cellular respiration
Correct Answer: The flow of gases into and out of the alveoli of the lungs
Rationale: Ventilation is the mechanical process of moving air into and out of the lungs, specifically the
alveoli. Diffusion is the exchange of gases between alveoli and blood. Transport of oxygen occurs via
hemoglobin, and cellular respiration occurs at the tissue level.
2. What is the term used to describe the ease or difficulty with which the lungs can be inflated?
A) Resistance
B) Compliance
C) Elasticity
D) Tidal volume
Correct Answer: Compliance
Rationale: Lung compliance reflects the distensibility of lung tissue—how easily the lungs can be
inflated. High compliance is seen in emphysema, while low compliance (stiff lungs) occurs in fibrosis or
pulmonary edema.
3. The diaphragm is innervated by which nerve roots?
A) T2–T4
,B) C3, C4, C5
C) L1–L3
D) S1–S2
Correct Answer: C3, C4, C5
Rationale: The phrenic nerve, originating from cervical nerve roots C3, C4, and C5, provides motor
innervation to the diaphragm. The mnemonic "C3, 4, 5 keeps the diaphragm alive" is commonly used to
remember this.
4. The breathing rate is determined by input from which receptors that monitor oxygen, carbon dioxide,
and pH levels in the blood?
A) Baroreceptors
B) Chemoreceptors
C) Stretch receptors
D) Nociceptors
Correct Answer: Chemoreceptors
Rationale: Chemoreceptors, both central (in the medulla) and peripheral (in carotid and aortic bodies),
sense changes in arterial oxygen, carbon dioxide, and pH. Their feedback modulates respiratory centers
to adjust ventilation and maintain homeostasis.
5. A reduction in blood O₂ levels is known as:
A) Hypoxia
B) Hypoxemia
C) Hypercapnia
D) Anoxia
Correct Answer: Hypoxemia
, Rationale: Hypoxemia specifically refers to decreased arterial oxygen tension (PaO₂), regardless of total
O₂ content or delivery. Hypoxia is a broader term for inadequate oxygen at the tissue level.
6. Which of the following statements about inspiration and expiration is TRUE?
A) Inspiration is passive, and expiration is active
B) Inspiration is active, and expiration is passive at rest
C) Both inspiration and expiration are active processes
D) Both inspiration and expiration are passive processes
Correct Answer: Inspiration is active, and expiration is passive at rest
Rationale: Inspiration requires contraction of the diaphragm and external intercostal muscles and is
therefore active. Expiration at rest is passive due to elastic recoil of the lungs. Expiratory muscles are
recruited only during forced expiration.
7. Even after forced expiration, a significant amount of air remains in the lungs. This is called:
A) Tidal volume
B) Vital capacity
C) Residual volume
D) Expiratory reserve volume
Correct Answer: Residual volume
Rationale: After maximal (forced) expiration, the residual volume (RV) remains in the lungs to prevent
collapse and maintain alveolar inflation. Tidal volume is the air moved during normal breathing, and vital
capacity is the maximum amount of air that can be exhaled after a maximal inhalation.
8. Both carbon dioxide and oxygen are able to bind with hemoglobin.
A) True
