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How does emphysema damage the alveoli where gas exchange occurs?
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respiratory disease
The bronchioles of the lungs are the site where oxygen is exchanged for carbon dioxide during the process of respiration. Inflammation, infection, or obstruction of the bronchioles is often associated with acute or chronic respiratory disease, including bronchiectasis, pneumonia, and lung abscesses.
Emphysema is a chronic, irreversible condition characterized by the widespread destruction of the lungs' gas-exchanging tissues. The disease damages the alveoli through the following processes:12
- Destruction of Alveolar Walls: The walls of the alveoli are destroyed, which leads to the loss of the delicate structures where gas exchange occurs.12
- Capillary Damage: The disease causes the destruction of the alveolar capillaries that surround these air sacs, further impairing the transfer of gases.1
- Reduced Surface Area: As a result of these structural losses, the total surface area available for the exchange of oxygen and carbon dioxide between inhaled air and the blood is significantly reduced.1
- Loss of Elasticity: The destruction of alveolar walls involves the loss of elastic tissue, which causes the lungs to overexpand and lose their ability to recoil, ultimately increasing resistance to airflow.12
This damage is often attributed to a protease-antiprotease imbalance, where enzymes that break down proteins damage lung tissue, a process frequently exacerbated by cigarette smoke.2