What happens to air as it moves through the conducting zone?

As air moves through the conducting zone of the respiratory system, it undergoes several critical processes that prepare it for gas exchange in the respiratory zone. The conducting zone includes structures such as the nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles.

During its passage through these structures, air is filtered to remove dust, pathogens, and other particles, primarily by the action of mucus and cilia lining the airways. Additionally, the air is warmed to match the body's internal temperature, which is essential for the proper function of the lungs and to prevent irritation of the respiratory epithelium. Moreover, the air is moistened, increasing the humidity level, which is vital for the efficient diffusion of gases and to protect the delicate tissues in the lungs.

This combination of filtering, warming, and moistening ensures that by the time the air reaches the alveoli, it is in the optimal condition for the exchange of oxygen and carbon dioxide.