Final answer:
Particles that are not filtered out by the respiratory epithelium or transported out by macrophages are coughed up during normal daily activities.
Step-by-step explanation:
Particles that are not filtered out by the respiratory epithelium or transported out by macrophages are coughed up during normal daily activities. The bronchi and bronchioles of the lungs contain cilia that help move mucus and other particles out of the lungs, and this continuous wave-like motion sweeps the particles upward toward the throat, where they can be expelled from the body. When foreign particles such as smoke and dust enter the respiratory system, the cilia in the airways trap and remove them through the process of coughing.