Final answer:
The ciliated epithelium of the tracheobronchial tree functions as a mucus-cilia escalator. It traps debris and pathogens in mucus and propels it upward toward the throat.
Step-by-step explanation:
The ciliated epithelium of the tracheobronchial tree has the function of a mucus-cilia escalator. It traps debris and pathogens in mucus secreted by goblet cells and propels the mucus with trapped particles upward toward the throat. The cilia move in a sweeping motion to create a continuous wave-like motion that helps to remove the mucus and particles from the airways. This mechanism plays a crucial role in preventing dust, germs, and other foreign particles from reaching the lungs and causing infections.