CPFT Practice Exam 2025 – Complete Test Prep Guide

In emphysema, the lungs undergo significant structural changes that affect various lung volumes, particularly the residual volume (RV). Emphysema is characterized by the destruction of the alveolar walls and loss of elastic recoil in the lung tissue. As a result, the airways can collapse during expiration, leading to a situation where air becomes trapped in the lungs.

This air trapping prevents all the air from being expelled, causing an accumulation of air in the alveoli and contributing to an increase in residual volume. Therefore, in patients with emphysema, the residual volume is elevated due to this inability to fully exhale, representing a hallmark of the disease.

Other options do not accurately reflect the physiological changes in emphysema. The residual volume does not remain constant, decrease, or remain unaffected; rather, it specifically increases due to the air trapping phenomenon associated with the loss of lung elasticity.