Nasal Cavity filters the air that we breath, the pharynx is also a passageway for air and it traps and kills bacteria the larynx is a doorway when we eat food the larynx closes (through the help of the epiglottis), the trachea(I forgot to put it) is just a passageway of air, the bronchi there is one for each lung and it has bronchioles, then it reaches the alveoli where the exchange of gases occur.
