American Registry of Radiologic Technologists (ARRT) Practice Exam

Emphysema is characterized by the over-distention of air in the alveoli, leading to a loss of elastic recoil in the lungs. This condition is one of the forms of chronic obstructive pulmonary disease (COPD) and is primarily caused by long-term exposure to irritants such as cigarette smoke or environmental pollutants.

In emphysema, the walls between the alveoli are destroyed, resulting in larger, but fewer alveoli. This structural change reduces the surface area available for gas exchange, causing difficulty in exhalation and trapping air in the lungs. Patients with emphysema often experience shortness of breath and capacity limitations during physical activities due to this air trapping and reduced lung function.

The other conditions mentioned, such as pneumothorax, asthma, and bronchitis, do not primarily involve the over-distention of air in the alveoli in the same manner or context as emphysema does. For example, pneumothorax refers to the presence of air in the pleural space, while asthma is characterized by bronchial hyperreactivity and inflammation leading to reversible obstruction of airflow. Bronchitis involves inflammation of the bronchial tubes, which can cause a productive cough and mucus production, but does not specifically involve