What is the primary role of the cilia in the respiratory system?

The primary role of cilia in the respiratory system is to filter inspired air. Cilia are tiny hair-like structures that line the respiratory tract, particularly in the nasal passages and the trachea. Their primary function is to trap and move particles, such as dust, pollen, and microorganisms, away from the airways and toward the throat, where they can be swallowed or expelled. This action is crucial for maintaining clear airways and protecting the lungs from potential pathogens and irritants that can cause infection or inflammation.

While other processes, such as the absorption of oxygen and gas exchange, are vital functions of the respiratory system, they are not directly related to the activity of cilia. The regulation of airflow is also important, but this function is more about the anatomy of the airways and the muscular control surrounding them rather than the action of cilia themselves. Thus, the filtering action of cilia is essential for respiratory health and efficiency.