|Maryville
1. Which immunoglobulin is primarily responsible for the type I hypersensitivity
reaction observed in extrinsic asthma?
A. IgG
B. IgM
C. IgA
D. IgE
Answer: D
Rationale: Extrinsic (atopic) asthma is driven by an IgE-mediated response to
environmental allergens, leading to mast cell degranulation and the release of
inflammatory mediators.
2. In the pathophysiology of ARDS, what is the primary cause of the initial lung
injury in the exudative phase?
A. Excessive surfactant production
B. Decreased pulmonary capillary hydrostatic pressure
C. Fibrosis of the basement membrane
D. Damage to the alveolar-capillary membrane
Answer: D
Rationale: The hallmark of early ARDS is damage to the alveolar-capillary membrane,
which increases permeability and leads to protein-rich fluid leaking into the alveoli.
,3. Which genetic deficiency is most strongly associated with the early
development of panacinar emphysema, especially in non-smokers?
A. BRCA1 mutation
B. Cystic Fibrosis Transmembrane Conductance Regulator mutation
C. Factor V Leiden mutation
D. Alpha-1 antitrypsin deficiency
Answer: D
Rationale: Alpha-1 antitrypsin inhibits proteases like neutrophil elastase; its deficiency
leads to unchecked destruction of alveolar walls, causing emphysema.
4. What is the pathophysiological hallmark of chronic bronchitis?
A. Destruction of alveolar septa
B. Obliteration of the pleural space
C. Reversible bronchospasm
D. Hypertrophy of mucus-secreting glands in the bronchial wall
Answer: D
Rationale: Chronic bronchitis is defined by mucus gland hypertrophy and goblet cell
hyperplasia, leading to chronic productive cough and airway obstruction.
5. A patient with a pulmonary embolism has a high V/Q ratio. This indicates
which of the following?
A. Normal ventilation and normal perfusion
B. Alveolar shunting (perfusion without ventilation)
C. Dead space ventilation (ventilation without perfusion)
D. Increased diffusion capacity
Answer: C
Rationale: A high V/Q ratio means ventilation is occurring but perfusion is blocked (as in
PE), creating alveolar dead space.
, 6. Which of the following is the primary stimulus for breathing in a healthy
individual?
A. High arterial carbon dioxide (PaCO2)
B. Low arterial oxygen (PaO2)
C. Decreased arterial pH
D. Increased bicarbonate levels
Answer: A
Rationale: Central chemoreceptors in the medulla are primarily sensitive to changes in
PaCO2 and pH of the cerebrospinal fluid, making CO2 the main drive for respiration.
7. In ‘Cor Pulmonale’, the right ventricular hypertrophy is a direct result of:
A. Left-sided heart failure
B. Aortic valve stenosis
C. Systemic hypertension
D. Pulmonary hypertension
Answer: D
Rationale: Cor pulmonale is right heart failure resulting from primary lung disease that
causes pulmonary hypertension, increasing the workload on the right ventricle.
8. Which type of lung cancer is most frequently associated with paraneoplastic
syndromes like SIADH or Cushing syndrome?
A. Adenocarcinoma
B. Squamous cell carcinoma
C. Small cell carcinoma
D. Large cell carcinoma
Answer: C
Rationale: Small cell lung cancer is a neuroendocrine tumor that often secretes hormones,
leading to various paraneoplastic syndromes.