What happens to lung function in age-related respiratory changes?

In the context of age-related respiratory changes, a decrease in pulmonary artery oxygen tension (PaO2) is a notable aspect. As people age, various physiological changes occur in the respiratory system. These changes include a decrease in the surface area available for gas exchange due to loss of alveolar units and the effects of fibrosis or atelectasis.

Additionally, the lung parenchyma becomes stiffer and less compliant, which can lead to atelectatic changes and reduced expiratory airflow, contributing to a decreased PaO2. This reduction in oxygen levels is further exacerbated by age-related changes in ventilation-perfusion (V/Q) matching and a diminished response in overall respiratory drive. Consequently, the combination of these factors leads to a decrease in PaO2, reflecting impaired gas exchange rather than improved respiratory function.

The other listed options do not accurately describe the changes seen in lung function with aging. For example, lung compliance typically decreases rather than improves, FEV1 generally declines as individuals age, and airway resistance tends to increase due to structural changes in the lung and airway walls, contributing to a more obstructive pattern in pulmonary function.