NURS 231/NURS231 Module 5 V3 |
Pathophysiology Q&A with Rationale | Portage
Learning
1. Which of the following describes the primary function of surfactant in the lungs?
A. To decrease surface tension and prevent alveolar collapse
B. To increase surface tension within the alveoli
C. To facilitate the diffusion of oxygen into the capillaries
D. To protect the lungs from bacterial infections
Correct Answer: A
Explanation: Surfactant is a lipoprotein complex produced by Type II alveolar cells. Its
primary role is to lower the surface tension at the air-liquid interface within the alveoli,
which prevents them from collapsing during expiration. Without adequate surfactant, the
work of breathing increases significantly, often leading to respiratory distress syndrome.
2. A patient is diagnosed with a ‘shunt’ V/Q mismatch. What does this specifically indicate?
A. Perfusion is adequate, but ventilation is lacking
B. Ventilation is adequate, but perfusion is lacking
C. Both ventilation and perfusion are absent
D. Airway resistance is decreased while blood flow is normal
Correct Answer: A
,Explanation: A shunt occurs when there is adequate blood flow (perfusion) to the alveoli,
but the air cannot reach them (ventilation) due to an obstruction or collapse. This results in
deoxygenated blood returning to the left side of the heart without participating in gas
exchange. It is a common cause of hypoxemia in conditions like atelectasis or pneumonia.
3. Which clinical manifestation is most characteristic of a tension pneumothorax?
A. Increased breath sounds on the affected side
B. Mediastinal shift toward the unaffected side
C. Bradypnea and hypertension
D. Resonance upon percussion of the chest wall
Correct Answer: B
Explanation: A tension pneumothorax occurs when air enters the pleural space but cannot
escape, causing a rapid increase in intrapleural pressure. This pressure buildup pushes the
heart and great vessels toward the opposite side, known as a mediastinal shift. It is a
medical emergency that can lead to obstructive shock and death if not treated immediately.
4. What is the primary underlying pathophysiology of extrinsic (atopic) asthma?
A. Irreversible destruction of the alveolar walls
B. Type I hypersensitivity reaction mediated by IgE
C. Chronic bacterial infection of the bronchioles
D. Alpha-1 antitrypsin deficiency resulting in lung damage
, Correct Answer: B
Explanation: Extrinsic asthma is triggered by environmental allergens such as pollen or
pet dander. These allergens stimulate the production of IgE antibodies, which bind to mast
cells and cause the release of inflammatory mediators like histamine. This process results
in bronchoconstriction, airway edema, and increased mucus production.
5. A patient presents with a chronic productive cough that has lasted for three months over
two consecutive years. This clinical history is diagnostic for:
A. Chronic Bronchitis
B. Acute Bronchiolitis
C. Emphysema
D. Pulmonary Fibrosis
Correct Answer: A
Explanation: Chronic bronchitis is defined clinically as a productive cough lasting at least
three months in at least two consecutive years. This condition is characterized by the
hypersecretion of mucus and hypertrophy of the goblet cells in the airways. It is often
associated with long-term cigarette smoking or exposure to environmental irritants.
6. Which of the following is a hallmark feature of emphysema?
A. Loss of lung elasticity and destruction of alveolar walls
B. Excessive mucus production and airway obstruction
Pathophysiology Q&A with Rationale | Portage
Learning
1. Which of the following describes the primary function of surfactant in the lungs?
A. To decrease surface tension and prevent alveolar collapse
B. To increase surface tension within the alveoli
C. To facilitate the diffusion of oxygen into the capillaries
D. To protect the lungs from bacterial infections
Correct Answer: A
Explanation: Surfactant is a lipoprotein complex produced by Type II alveolar cells. Its
primary role is to lower the surface tension at the air-liquid interface within the alveoli,
which prevents them from collapsing during expiration. Without adequate surfactant, the
work of breathing increases significantly, often leading to respiratory distress syndrome.
2. A patient is diagnosed with a ‘shunt’ V/Q mismatch. What does this specifically indicate?
A. Perfusion is adequate, but ventilation is lacking
B. Ventilation is adequate, but perfusion is lacking
C. Both ventilation and perfusion are absent
D. Airway resistance is decreased while blood flow is normal
Correct Answer: A
,Explanation: A shunt occurs when there is adequate blood flow (perfusion) to the alveoli,
but the air cannot reach them (ventilation) due to an obstruction or collapse. This results in
deoxygenated blood returning to the left side of the heart without participating in gas
exchange. It is a common cause of hypoxemia in conditions like atelectasis or pneumonia.
3. Which clinical manifestation is most characteristic of a tension pneumothorax?
A. Increased breath sounds on the affected side
B. Mediastinal shift toward the unaffected side
C. Bradypnea and hypertension
D. Resonance upon percussion of the chest wall
Correct Answer: B
Explanation: A tension pneumothorax occurs when air enters the pleural space but cannot
escape, causing a rapid increase in intrapleural pressure. This pressure buildup pushes the
heart and great vessels toward the opposite side, known as a mediastinal shift. It is a
medical emergency that can lead to obstructive shock and death if not treated immediately.
4. What is the primary underlying pathophysiology of extrinsic (atopic) asthma?
A. Irreversible destruction of the alveolar walls
B. Type I hypersensitivity reaction mediated by IgE
C. Chronic bacterial infection of the bronchioles
D. Alpha-1 antitrypsin deficiency resulting in lung damage
, Correct Answer: B
Explanation: Extrinsic asthma is triggered by environmental allergens such as pollen or
pet dander. These allergens stimulate the production of IgE antibodies, which bind to mast
cells and cause the release of inflammatory mediators like histamine. This process results
in bronchoconstriction, airway edema, and increased mucus production.
5. A patient presents with a chronic productive cough that has lasted for three months over
two consecutive years. This clinical history is diagnostic for:
A. Chronic Bronchitis
B. Acute Bronchiolitis
C. Emphysema
D. Pulmonary Fibrosis
Correct Answer: A
Explanation: Chronic bronchitis is defined clinically as a productive cough lasting at least
three months in at least two consecutive years. This condition is characterized by the
hypersecretion of mucus and hypertrophy of the goblet cells in the airways. It is often
associated with long-term cigarette smoking or exposure to environmental irritants.
6. Which of the following is a hallmark feature of emphysema?
A. Loss of lung elasticity and destruction of alveolar walls
B. Excessive mucus production and airway obstruction
