What is the difference between the nasal cavity and the sinuses?

What is the difference between the nasal cavity and the sinuses?

Richard Sheldon (Medical Advisor to the CA State Respiratory Care Board) gives expert video advice on: How is a pulmonologist different from other doctors?; What is the difference between the nasal cavity and the sinuses? and more...

The nasal cavity is where the nose heads back toward the back of the throat, and the sinuses are off to the side. They do various functions like: help to humidify the air, and they give some resonance to your voice. They are not part of the nasal cavity other than they do drain into it but they have different structures. They have different mucosal linings, and they are specialized, whereas the nasal cavity itself is just a conduit, an open vestibule if you will, to take the air from the nose all the way to the back of the throat and down into the trachea.