BIOL 252 The respiratory system Exam with Questions and Answers

It covers key domains which include; Functional Anatomy of the Respiratory Tract, Mechanics of Ventilation, Gas Exchange and Transport, Control of Respiration and Clinical Correlations and Pathophysiology. A 62-year-old man with a long history of smoking presents with progressive dyspnea and a chronic productive cough. Pulmonary function testing shows decreased FEV1/FVC ratio and hyperinflated lungs. Which pathophysiological mechanism best explains his condition? a. Increased elastic recoil due to fibrosis b. Destruction of alveolar walls leading to loss of elastic recoil c. Thickening of the alveolar-capillary membrane due to edema d. Bronchial smooth muscle hypertrophy without structural damage Correct Answer: b. Destruction of alveolar walls leading to loss of elastic recoil Rationale: Chronic smoking is strongly associated with emphysema, a form of COPD characterized by destruction of alveolar walls. This leads to decreased elastic recoil, air trapping, and hyperinflation. The reduced FEV1/FVC ratio confirms obstructive pathology. Fibrosis would increase recoil, not decrease it, and edema or smooth muscle hypertrophy alone would not explain alveolar destruction.