The nose is the main entrance to your respiratory system. It is lined with a mucous membrane that contains many tiny blood vessels close to the surface. The front of the nose also has protective hairs. The nasal lining filters, moistens, and warms the air you breathe as it goes through the nasal passage toward your throat and lungs. The nasal passage runs along the top of the palate, or the shelf separating the nose from the mouth, and turns downward to join the passage from the mouth to the throat.The nasal passage is not a simple tube. A series of baffles called turbinates make the passage winding rather than straight. Also, in several places, it branches into sinuses, which are pairs of air-filled cavities in the bones of the skull. Nasal infections, which are discussed in the following articles, sometimes spread into the sinuses as well as into the rest of the respiratory system.
The nose is also the organ of smell, and you may not be able to smell anything if a disorder “stuffs up” your nose. Permanent loss of smell is rare.