Emphysema's Impact on Alveolar Structure

Steps:

• Define emphysema as a COPD where alveolar walls break down due to enzyme imbalance.
• Note primary effects: alveoli enlarge and burst, elastin fibers degrade, reducing lung recoil.
• Identify secondary effect: fewer capillaries from lost alveolar surface area, impairing gas exchange.
• Match effects to options: only A aligns with bursting, elastin loss, and capillary decrease.

Why A is correct:

• Emphysema destroys alveolar septa, causing burst alveoli, elastin degradation, and capillary reduction per medical pathology definitions.

Why the others are wrong:

• B: Elastin increases contradict emphysema's proteolytic destruction.
• C: Alveoli shrink describes restrictive diseases, not emphysema's destructive enlargement.
• D: Both shrinking and elastin increase oppose emphysema's bursting and elastin loss.

Final answer: A