How the Nose Works The nose on your face is just the tip of an
iceberg. The important functions--breathing and smelling--
actually happen mostly inside your head, in your nasal cavity.
The air inhaled through your nostrils travels to this cavity on
its way to the lungs. The nasal cavity cleans and conditions the
air. Pollutants, viruses and bacteria are trapped in mucus,
which then travels to the stomach, where stomach acid
neutralizes the germs. Three structures on the sides of the
cavity, called the turbinates, humidify the air. By the time air
reaches the lungs, it's almost completely saturated with water
vapor. The water vapor is essential for proper function of the
lungs. It's also crucial that air reaching the lungs be neither
too cold nor too hot. In winter, the membranes in the nasal
cavity raise the temperature of the air you breathe so your
lungs never feel the bitter cold. While scientists understand
the nose and breathing, its ability to smell remains somewhat
mysterious. At the rear of the nasal c