NUR 5461/NUR5461 Module 3 V1 |
Pulmonary System Q&A with Rationale |
William Paterson University
1. Which cell type is primarily responsible for the secretion of surfactant within the alveoli?
A. Type II Alveolar Cells
B. Type I Alveolar Cells
C. Alveolar Macrophages
D. Goblet Cells
Correct Answer: A
Expert Explanation: Type II alveolar cells are specialized epithelial cells that produce and
secrete surfactant. Surfactant is a lipoprotein complex that reduces surface tension at the
air-liquid interface of the lung. This action prevents the alveoli from collapsing during
expiration and reduces the overall work of breathing.
2. A patient has a shift to the right in the oxyhemoglobin dissociation curve. Which
physiological state most likely caused this?
A. Alkalosis
B. Hypothermia
C. Decreased 2,3-DPG
D. Increased PCO2
,Correct Answer: D
Expert Explanation: An increase in PCO2, which is associated with acidosis, causes the
oxyhemoglobin dissociation curve to shift to the right. This shift indicates that hemoglobin
has a lower affinity for oxygen, making it easier for oxygen to be released to the tissues.
This is an adaptive mechanism to increase oxygen delivery when metabolic demands are
high.
3. What is the primary pathophysiology behind the development of a barrel chest in patients
with emphysema?
A. Chronic inflammation of the bronchioles
B. Excessive mucus production in the large airways
C. Air trapping and alveolar hyperinflation
D. Fluid accumulation in the pleural space
Correct Answer: C
Expert Explanation: In emphysema, the destruction of alveolar walls and loss of elastic
recoil lead to air trapping during expiration. This results in permanent hyperinflation of the
lungs, which expands the thoracic cavity. Over time, the increased anterior-posterior
diameter of the chest gives it a characteristic ‘barrel’ appearance.
4. Which of the following describes the ‘shunting’ form of V/Q mismatch?
A. Ventilation is normal, but perfusion is absent.
B. Perfusion is normal, but ventilation is absent.
, C. Both ventilation and perfusion are absent.
D. Perfusion exceeds ventilation in the apex of the lung.
Correct Answer: B
Expert Explanation: Shunting occurs when blood passes through portions of the
pulmonary capillary bed that receive no ventilation. This results in deoxygenated blood
returning to the left side of the heart, contributing to hypoxemia. Common causes include
atelectasis, pneumonia, and pulmonary edema where alveoli are filled with fluid.
5. In the context of ARDS, what occurs during the exudative phase?
A. Increased capillary permeability and alveolar edema
B. Widespread pulmonary fibrosis
C. Proliferation of Type II pneumocytes
D. Resolution of the inflammatory response
Correct Answer: A
Expert Explanation: The exudative phase of ARDS is characterized by intense
inflammation that damages the alveolar-capillary membrane. This damage leads to
increased permeability, allowing protein-rich fluid to leak into the alveoli. This phase
typically occurs within the first 24 to 72 hours after the initial lung injury.
6. Which clinical finding is pathognomonic for a tension pneumothorax?
A. Bilateral wheezing
Pulmonary System Q&A with Rationale |
William Paterson University
1. Which cell type is primarily responsible for the secretion of surfactant within the alveoli?
A. Type II Alveolar Cells
B. Type I Alveolar Cells
C. Alveolar Macrophages
D. Goblet Cells
Correct Answer: A
Expert Explanation: Type II alveolar cells are specialized epithelial cells that produce and
secrete surfactant. Surfactant is a lipoprotein complex that reduces surface tension at the
air-liquid interface of the lung. This action prevents the alveoli from collapsing during
expiration and reduces the overall work of breathing.
2. A patient has a shift to the right in the oxyhemoglobin dissociation curve. Which
physiological state most likely caused this?
A. Alkalosis
B. Hypothermia
C. Decreased 2,3-DPG
D. Increased PCO2
,Correct Answer: D
Expert Explanation: An increase in PCO2, which is associated with acidosis, causes the
oxyhemoglobin dissociation curve to shift to the right. This shift indicates that hemoglobin
has a lower affinity for oxygen, making it easier for oxygen to be released to the tissues.
This is an adaptive mechanism to increase oxygen delivery when metabolic demands are
high.
3. What is the primary pathophysiology behind the development of a barrel chest in patients
with emphysema?
A. Chronic inflammation of the bronchioles
B. Excessive mucus production in the large airways
C. Air trapping and alveolar hyperinflation
D. Fluid accumulation in the pleural space
Correct Answer: C
Expert Explanation: In emphysema, the destruction of alveolar walls and loss of elastic
recoil lead to air trapping during expiration. This results in permanent hyperinflation of the
lungs, which expands the thoracic cavity. Over time, the increased anterior-posterior
diameter of the chest gives it a characteristic ‘barrel’ appearance.
4. Which of the following describes the ‘shunting’ form of V/Q mismatch?
A. Ventilation is normal, but perfusion is absent.
B. Perfusion is normal, but ventilation is absent.
, C. Both ventilation and perfusion are absent.
D. Perfusion exceeds ventilation in the apex of the lung.
Correct Answer: B
Expert Explanation: Shunting occurs when blood passes through portions of the
pulmonary capillary bed that receive no ventilation. This results in deoxygenated blood
returning to the left side of the heart, contributing to hypoxemia. Common causes include
atelectasis, pneumonia, and pulmonary edema where alveoli are filled with fluid.
5. In the context of ARDS, what occurs during the exudative phase?
A. Increased capillary permeability and alveolar edema
B. Widespread pulmonary fibrosis
C. Proliferation of Type II pneumocytes
D. Resolution of the inflammatory response
Correct Answer: A
Expert Explanation: The exudative phase of ARDS is characterized by intense
inflammation that damages the alveolar-capillary membrane. This damage leads to
increased permeability, allowing protein-rich fluid to leak into the alveoli. This phase
typically occurs within the first 24 to 72 hours after the initial lung injury.
6. Which clinical finding is pathognomonic for a tension pneumothorax?
A. Bilateral wheezing
