Bronchiectasis is defined as permanent dilation of bronchi and bronchioles due to destruction of which tissues?

• A. Bronchi and bronchioles due to destruction of muscle and elastic tissue
• B. Alveolar walls due to infection
• C. Airways with goblet cell hyperplasia
• D. Pleural lining due to scarring

Answer: (A)

Bronchiectasis arises when the supportive framework of the bronchi is damaged, specifically the muscular and elastic tissue in the bronchial walls. When elastic fibers and smooth muscle are destroyed by chronic inflammation and infection, the airways lose their recoil and structural integrity, leading to permanent dilation of the bronchi and bronchioles. This is distinct from processes that affect alveolar walls (as in emphysema), goblet cell hyperplasia (which increases mucus production without causing dilation), or pleural scarring (which affects the lining around the lungs, not the airway walls). The key idea is that loss of the airway wall components that provide structure—muscle and elastic tissue—produces the irreversible widening characteristic of bronchiectasis.