What moistens and filters incoming air?

The respiratory system, specifically the nasal cavity, moistens and filters incoming air. The mucous membranes lining the nasal passages produce mucus that traps dust, allergens, and pathogens, while the moisture in the air helps to humidify it before it reaches the lungs. Additionally, tiny hair-like structures called cilia help move trapped particles out of the respiratory system. This process is essential for protecting the lungs and ensuring optimal gas exchange.