In a one-week smoke exposure study, which pulmonary defense parameter increases?

In a one-week smoke exposure study, which pulmonary defense parameter increases?

• A. Alveolar Macrophage Function up
• B. Reid index unchanged
• C. Alveolar Cilia function down
• D. Mucus Production and Secretion up

Answer: (D)

Smoky irritants provoke the airway to secrete more mucus as an immediate defense. The goblet cells and submucosal glands respond to irritation by increasing mucus production and secretion to trap and remove particulates, so this parameter rises quickly with smoke exposure. In contrast, alveolar macrophage function is typically suppressed by cigarette smoke, not upregulated, and ciliary function is damaged (cilia beat and clearance decline) rather than enhanced. The Reid index reflects mucous gland and goblet cell hyperplasia relative to airway wall thickness; significant changes in that ratio come with longer-term, chronic exposure, not just one week. So mucus production and secretion up is the best-fit increase in the short term.

Smoky irritants provoke the airway to secrete more mucus as an immediate defense. The goblet cells and submucosal glands respond to irritation by increasing mucus production and secretion to trap and remove particulates, so this parameter rises quickly with smoke exposure. In contrast, alveolar macrophage function is typically suppressed by cigarette smoke, not upregulated, and ciliary function is damaged (cilia beat and clearance decline) rather than enhanced. The Reid index reflects mucous gland and goblet cell hyperplasia relative to airway wall thickness; significant changes in that ratio come with longer-term, chronic exposure, not just one week. So mucus production and secretion up is the best-fit increase in the short term.