D236 Respiratory Disorders Pathophysiology (COPD, ARDS, Asthma)
2026 |WGU
1. Which immunoglobulin is primarily involved in the Type I hypersensitivity
reaction seen in extrinsic asthma?
A. IgE
B. IgM
C. IgG
D. IgA
Answer: A
Rationale: IgE is the primary antibody involved in allergic asthma, binding to mast cells
and triggering degranulation upon allergen exposure.
2. What is the hallmark physiological feature of Acute Respiratory Distress
Syndrome (ARDS)?
A. Reversible bronchospasm
B. Refractory hypoxemia
C. Increased lung compliance
D. Chronic mucus production
Answer: B
Rationale: Refractory hypoxemia, which is low arterial oxygen despite high concentrations
of inspired oxygen, is the hallmark of ARDS due to significant shunting.
,3. In emphysema, the destruction of alveolar walls is primarily caused by an
imbalance between which two substances?
A. Histamine and Leukotrienes
B. Surfactant and Mucus
C. Proteases and Antiproteases
D. Oxygen and Carbon dioxide
Answer: C
Rationale: Emphysema involves the destruction of alveolar walls because of an imbalance
where proteases (like elastase) overwhelm antiproteases (like alpha-1 antitrypsin).
4. Chronic bronchitis is clinically defined by a productive cough lasting at least:
A. 3 months in 2 consecutive years
B. 6 months in 1 year
C. 2 weeks after a viral infection
D. 1 month every year for 5 years
Answer: A
Rationale: Chronic bronchitis is defined as a productive cough for at least 3 months in at
least 2 consecutive years.
5. Which cell type is responsible for the ‘remodeling’ of airways in chronic
asthma?
A. Fibroblasts and Smooth Muscle Cells
B. Erythrocytes
C. Neutrophils
D. Alveolar Macrophages
Answer: A
Rationale: Airway remodeling involves structural changes including subepithelial fibrosis
and smooth muscle hypertrophy driven by fibroblasts and myocytes.
, 6. What occurs during the ‘exudative’ phase of ARDS?
A. Resolution of pulmonary edema
B. Proliferation of Type II pneumocytes
C. Extensive lung fibrosis
D. Formation of hyaline membranes
Answer: D
Rationale: The exudative phase (first 7 days) is characterized by interstitial edema and the
formation of protein-rich hyaline membranes in the alveoli.
7. Which condition is characterized by ‘air trapping’ and an increased residual
volume?
A. Pneumonia
B. Pneumothorax
C. Pulmonary Fibrosis
D. COPD
Answer: D
Rationale: In COPD, particularly emphysema, the loss of elastic recoil and airway collapse
lead to air trapping and hyperinflation, increasing residual volume.
8. What is the primary role of Alpha-1 Antitrypsin?
A. To stimulate mucus production
B. To increase capillary permeability
C. To promote bronchoconstriction
D. To inhibit neutrophil elastase
Answer: D
Rationale: Alpha-1 Antitrypsin is a protective enzyme that inhibits neutrophil elastase,
preventing the breakdown of elastin in lung tissue.
2026 |WGU
1. Which immunoglobulin is primarily involved in the Type I hypersensitivity
reaction seen in extrinsic asthma?
A. IgE
B. IgM
C. IgG
D. IgA
Answer: A
Rationale: IgE is the primary antibody involved in allergic asthma, binding to mast cells
and triggering degranulation upon allergen exposure.
2. What is the hallmark physiological feature of Acute Respiratory Distress
Syndrome (ARDS)?
A. Reversible bronchospasm
B. Refractory hypoxemia
C. Increased lung compliance
D. Chronic mucus production
Answer: B
Rationale: Refractory hypoxemia, which is low arterial oxygen despite high concentrations
of inspired oxygen, is the hallmark of ARDS due to significant shunting.
,3. In emphysema, the destruction of alveolar walls is primarily caused by an
imbalance between which two substances?
A. Histamine and Leukotrienes
B. Surfactant and Mucus
C. Proteases and Antiproteases
D. Oxygen and Carbon dioxide
Answer: C
Rationale: Emphysema involves the destruction of alveolar walls because of an imbalance
where proteases (like elastase) overwhelm antiproteases (like alpha-1 antitrypsin).
4. Chronic bronchitis is clinically defined by a productive cough lasting at least:
A. 3 months in 2 consecutive years
B. 6 months in 1 year
C. 2 weeks after a viral infection
D. 1 month every year for 5 years
Answer: A
Rationale: Chronic bronchitis is defined as a productive cough for at least 3 months in at
least 2 consecutive years.
5. Which cell type is responsible for the ‘remodeling’ of airways in chronic
asthma?
A. Fibroblasts and Smooth Muscle Cells
B. Erythrocytes
C. Neutrophils
D. Alveolar Macrophages
Answer: A
Rationale: Airway remodeling involves structural changes including subepithelial fibrosis
and smooth muscle hypertrophy driven by fibroblasts and myocytes.
, 6. What occurs during the ‘exudative’ phase of ARDS?
A. Resolution of pulmonary edema
B. Proliferation of Type II pneumocytes
C. Extensive lung fibrosis
D. Formation of hyaline membranes
Answer: D
Rationale: The exudative phase (first 7 days) is characterized by interstitial edema and the
formation of protein-rich hyaline membranes in the alveoli.
7. Which condition is characterized by ‘air trapping’ and an increased residual
volume?
A. Pneumonia
B. Pneumothorax
C. Pulmonary Fibrosis
D. COPD
Answer: D
Rationale: In COPD, particularly emphysema, the loss of elastic recoil and airway collapse
lead to air trapping and hyperinflation, increasing residual volume.
8. What is the primary role of Alpha-1 Antitrypsin?
A. To stimulate mucus production
B. To increase capillary permeability
C. To promote bronchoconstriction
D. To inhibit neutrophil elastase
Answer: D
Rationale: Alpha-1 Antitrypsin is a protective enzyme that inhibits neutrophil elastase,
preventing the breakdown of elastin in lung tissue.
