What helps to keep the airways clear in the respiratory system?

• A. Muscle contractions
• B. Mucus
• C. Air pressure changes
• D. Blood flow

Answer: (B)

Mucus plays a vital role in keeping the airways clear within the respiratory system. It is produced by goblet cells and mucous glands located in the lining of the respiratory tract. This sticky substance traps dust, pathogens, and other particulate matter that enter the airways during breathing. By capturing these particles, mucus helps to prevent them from reaching the sensitive lung tissue, thus reducing the risk of infection and maintaining overall airway health.

Additionally, tiny hair-like structures called cilia sweep the trapped mucus upwards towards the throat, where it can be either swallowed or expelled. This mucociliary clearance mechanism is essential for keeping the airways unobstructed and ensuring efficient respiratory function. Overall, the presence of mucus and its functional properties are key components in maintaining airway integrity and protecting the respiratory system from irritants and infections.