Question

What leads to the collapsing of air passages due to smoking?

• A. Destruction of the elastic fibres in bronchioles by protein destroying chemicals
• B. Accumulation of mucus on the fibres
• C. Constant inhalation and exhalation leads to weakening of the elastic fibres in the bronchioles
• D. Both A and B

Answer 1

The correct option is A Destruction of the elastic fibres in bronchioles by protein destroying chemicals

Bronchioles present inside the lungs are made up of elastic fibres containing the elastin protein. These fibres help keep the small airways open. Due to accumulation of pathogens in the respiratory passage, alveolar macrophages are activated, that release protein-destroying chemicals. These chemicals destroy the elastin proteins leading to collapse of the air passages.