And the mucous membrane, as I mentioned earlier, is also found within our nasal cavity of the nose. Now, we also have tiny hairlike structures found along the cells lining the airways, and these can help carry the pollutants to our pharynx. So if we take a look at the diagram of our respiratory system, this is our trachea, these are the bronchi. These are our bronchioles. And if we zoom in on the terminal portion of our bronchioles, we get our alveolar. And we'll see how the alveolar also helps us protect from these pollutants in just a moment.