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

The primary function of cilia in the respiratory system is to trap and remove particles and pathogens. Cilia are tiny, hair-like structures that line the airways. They move in a coordinated manner, creating a sweeping motion that helps to push mucus, along with trapped dust, dirt, and microorganisms, upward towards the throat. This mechanism is vital for maintaining clear airways and preventing infections, as it helps to clear out contaminants that could otherwise cause respiratory issues. The effectiveness of the ciliary action plays a crucial role in the body's defense against respiratory diseases.

Other functions, such as producing mucus or providing structural support, are performed by different components of the respiratory system. Mucus is secreted by goblet cells, while structural support primarily comes from cartilage rings in the trachea. Gas exchange primarily occurs in the alveoli, not through cilia, emphasizing that cilia's main role centers on the clearance of pathogens and debris from the airways.