What is the primary function of mucus in the respiratory system?

Mucus plays a critical role in the respiratory system primarily by protecting and moisturizing the airway surfaces. It serves as a barrier that traps dust, pathogens, and other foreign particles, which helps to prevent these irritants from reaching the sensitive tissues of the lungs. Additionally, mucus maintains moisture in the airways, which is essential for the proper functioning of the respiratory tract. This moist environment helps facilitate gas exchange and ensures that the respiratory surfaces remain healthy and effective.

While mucus also has a role in filtering air particles, transportation of oxygen, and regulating temperature, its fundamental function centers on protection and moisture retention. This is vital for maintaining the overall health of the respiratory system and ensuring efficient breathing.