,NURS 231 / BIOD 331 Pathophysiology Module 5 Exam |
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. 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 the activity of
respiratory centers to adjust ventilation and maintain homeostasis.
3. Lung _____ is the term used to describe the ease or difficulty with which the lungs can be inflated.
A) Compliance
B) Resistance
C) Elasticity
,D) Tidal volume
Correct Answer: Compliance
Rationale: Lung compliance refers to the distensibility of the lungs and chest wall. High compliance
indicates the lungs inflate easily, while low compliance reflects stiffer lungs that are more difficult to
inflate, characteristic of restrictive lung diseases.
4. 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 principal muscle of respiration. The mnemonic "C3, 4, 5 keeps the
diaphragm alive" is commonly used to remember this.
5. Which statement 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.
, 6. Both carbon dioxide and oxygen are able to bind with hemoglobin.
A) True
B) False
Correct Answer: True
Rationale: Hemoglobin binds oxygen at its heme groups and carbon dioxide at a separate site on the
globin chains, forming carbaminohemoglobin. This dual binding capacity is essential for effective gas
exchange.
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 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. Hypoventilation is associated with:
A) Decreased PCO₂
B) Increased PCO₂
C) Decreased PO₂ only
D) Normal PCO₂
Correct Answer: Increased PCO₂
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. 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 the activity of
respiratory centers to adjust ventilation and maintain homeostasis.
3. Lung _____ is the term used to describe the ease or difficulty with which the lungs can be inflated.
A) Compliance
B) Resistance
C) Elasticity
,D) Tidal volume
Correct Answer: Compliance
Rationale: Lung compliance refers to the distensibility of the lungs and chest wall. High compliance
indicates the lungs inflate easily, while low compliance reflects stiffer lungs that are more difficult to
inflate, characteristic of restrictive lung diseases.
4. 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 principal muscle of respiration. The mnemonic "C3, 4, 5 keeps the
diaphragm alive" is commonly used to remember this.
5. Which statement 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.
, 6. Both carbon dioxide and oxygen are able to bind with hemoglobin.
A) True
B) False
Correct Answer: True
Rationale: Hemoglobin binds oxygen at its heme groups and carbon dioxide at a separate site on the
globin chains, forming carbaminohemoglobin. This dual binding capacity is essential for effective gas
exchange.
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 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. Hypoventilation is associated with:
A) Decreased PCO₂
B) Increased PCO₂
C) Decreased PO₂ only
D) Normal PCO₂
Correct Answer: Increased PCO₂
