Pulmonary Mechanics & Ventilation

By completing this question set, you will be able to define lung volumes and capacities, identify which measurements require body plethysmography, and predict volume changes in obstructive and restrictive disease patterns. You will apply the compliance concept to predict how changes in elastic fibers, surfactant, and chest wall properties affect the ease of lung inflation, and use LaPlace's law to explain surfactant's role in alveolar stability. You will apply Poiseuille's law to predict how changes in airway radius affect resistance, identify the site of greatest airway resistance, and explain the equal pressure point concept and dynamic airway compression during forced expiration. You will calculate minute and alveolar ventilation, distinguish anatomic from physiologic dead space, apply the Bohr equation, and explain the inverse relationship between alveolar ventilation and PaCO₂. You will trace pressure changes during the normal breathing cycle, predict the consequences of pneumothorax on intrapleural pressure and lung expansion, and distinguish between negative-pressure and positive-pressure ventilation. Finally, you will distinguish elastic from resistive work of breathing, predict how patients with obstructive and restrictive disease optimize their breathing patterns, and explain the pathophysiology of auto-PEEP, diaphragm flattening, and pursed-lip breathing.