A 62-year-old man is a smoker with a 10-year history of cough productive of copious mucopurulent sputum. Over the past 6 months, he has developed progressive dyspnea. Physical examination shows bilateral pedal edema and a soft but enlarged liver. A chest radiograph shows bilateral pleural effusions and a prominent right heart border. Arterial blood gas values are Po2, 60 mm Hg; Pco2, 52 mm Hg; pH, 7.30; and HCO3-, 29 mEq/L. He is intubated and placed on a ventilator, and he requires increasing amounts of oxygen. Which of the following microscopic findings is most likely to be present in the affected lungs?

Correct Answer: D

Rationale: Hypertrophy of bronchial submucosal glands (D) marks chronic bronchitis (Page 30, Ans: D). Smoking and cough (>3 months, 2 years) with cor pulmonale (edema, effusions) reflect mucus hypersecretion (100 mL/day). Granulomas (A) fit sarcoidosis. Carcinoma (B) masses. Fibrosis (C) is restrictive. D's histologic change unlike A's granulomas drives obstruction, per document.

Correct Answer: D

Rationale: Asthma (D) causes reversible bronchoconstriction . B-agonists reverse spasms , unlike irreversible bronchiectasis (A), bronchitis (B), and emphysema (C). D's reversibility versus B's chronicity defines it, per document.

Correct Answer: D

Rationale: Poor blood supply (D) isn't an alveolar feature . Alveoli (300 million) boast a 70 m^2 surface (A), 0.2 μm walls (B), and surfactant (C) to prevent collapse, with rich capillaries (Page 5, Q11J) not poor (D). Efficient O2 diffusion (50 mL/min) demands vascularity. D's falsity unlike A's expanse or C's tension reduction contradicts alveolar design, per document.

Correct Answer: C

Rationale: Asthma's airway obstruction increases breathing work (C) via bronchoconstriction. Wheezing dominates expiration (A, false) as air traps (Q15). Bronchodilators (e.g., albuterol) relieve it (B, false). FEV1 drops (D, false) due to reduced flow (FEV1/FVC < 70%, Q46). C's effort diaphragm flattening, accessory muscles rises (e.g., 1-2% O2 consumption to 5-10%), unlike A's inspiratory bias or D's spirometry error, per obstructive physiology.

Correct Answer: B

Rationale: Oxygen's atmospheric percentage (21%) exceeds CO2's (0.04%) (B), but its solubility in blood (0.024 mL/mmHg/dL) is lower than CO2's (0.57 mL/mmHg/dL) . O2's higher presence drives diffusion (PIO2 ~150 mmHg vs. PICO2 ~0.3 mmHg), yet 98% binds hemoglobin dissolved O2 is minor (1.5% at PaO2 100 mmHg). CO2's solubility aids 10% dissolved transport, with 70% as HCO3-. B's contrast unlike A's reversal matches gas laws and physiology's transport mechanisms.