The respiratory distress that accompanies emphysema is caused by:
options: a) repeated exposure to cigarette smoke. b) chronic stretching of the alveolar walls. c) massive constriction of the bronchioles. d) acute fluid accumulation in the alveoli.
The correct answer and explanation is:
The correct answer is b) chronic stretching of the alveolar walls.
Emphysema is a chronic respiratory condition that primarily results from long-term damage to the lungs, often due to smoking or other environmental pollutants. This damage leads to the destruction of the alveolar walls, which are tiny air sacs in the lungs where gas exchange occurs. The primary cause of the respiratory distress in emphysema is the chronic stretching and enlargement of the alveoli, which reduces the surface area available for gas exchange.
As emphysema progresses, the alveolar walls lose their elasticity, and the small air sacs combine into larger, less efficient sacs. This leads to a decreased ability to transfer oxygen from the lungs into the blood, as well as reduced capacity to expel carbon dioxide. The airways become less effective at holding open the alveoli during exhalation, causing air to become trapped in the lungs. This air trapping results in difficulty breathing, especially during exhalation.
The damage to the alveolar walls is caused by prolonged inflammation in the lungs. Inflammation is triggered by exposure to harmful substances like cigarette smoke, pollutants, or other irritants. This inflammation breaks down the proteins that help maintain the structural integrity of the alveoli, leading to their collapse or enlargement.
The chronic stretching of the alveolar walls also leads to a loss of lung elasticity. Healthy lungs are able to recoil and expel air during exhalation, but in emphysema, the lungs lose this recoil, making it harder to breathe out and leading to increased air trapping. This is a key feature of the disease and is responsible for the progressive shortness of breath and respiratory distress that individuals with emphysema experience.