Final answer:
Pulmonary fibrosis and stiff chest wall are examples of restrictive diseases, where the lung's ability to expand is limited, leading to decreased lung compliance and trapped air in the lungs.
Step-by-step explanation:
Pulmonary fibrosis and stiff chest wall are examples of restrictive diseases. These conditions are characterized by a decrease in the compliance of lung tissue, making it difficult for the lungs to expand and fill with air. In restrictive diseases, the lung tissue becomes stiff or fibrotic, leading to a more positive intrapleural pressure, the collapse of airways upon exhalation, and trapping air in the lungs. This results in a significant decrease in Forced or Functional Vital Capacity (FVC) and a prolonged time to exhale air. Spirometry can be used to detect these conditions, as it measures the rate at which air can be inhaled and exhaled from the lungs, helping to diagnose restrictive lung diseases.