Nasal Disease Handbook

Anatomy And Physiology

I like to think of the nose as a bony tunnel in the middle of one's face. Air passes in and out of this tunnel. The back of the tunnel connects with the top of one's throat. The tunnel is divided in half by a piece of bone and cartilage. This is your nasal septum. In a few people it is straight, but in most of us it is crooked; so it is only a matter of degree as to how crooked or deviated. The septum divides the nose into two halves.

Protruding down into each nasal passage are three small mucosal covered bones. These are called turbinates. They increase the filtering, warming surface of each nasal cavity. Residing to the side of the nose, underneath your eyes and up into your forehead are large air pockets in the facial bones. These connect with the nasal cavity. They are called sinuses or more correctly paranasal sinuses. They are named the maxillary, ethmoid, frontal and sphenoid sinuses. The nose and the paranasal sinuses are lined with tissue which is called mucosa. The mucosa has little hairs called cilia and floating over these hairs is a layer of fluid. On top of the fluid layer floats a layer of mucus. The cilia beat back and forth in the fluid layer and they move or propel the mucus blanket along, out of your sinuses into your nose. The mucus blanket is then transported to the back of your throat. Under normal circumstances the mucus is swallowed. In a normal functioning nose a quart or more of fluid is generated daily, carried to the back of the nose and swallowed. This whole system is called the mucociliary transport system and it is the key to nasal health. Particulate materials such as dust, or bacteria become trapped in the mucus blanket and the cilia carry these to the back of your nose where they are swallowed and killed or digested when they reach your stomach. If the mucociliary system becomes impaired, then nasal and sinus secretions stagnate. They become infected by the bacteria which are always present within your nose and infection develops, be it in your nose or your sinuses.

The smell receptors, or olfactory receptors as they are properly called, reside in the very uppermost portions of your nose. The nose must be reasonably open for odors to be carried to the roof. Here the odors are perceived and if the system is intact and functioning, you are able to smell roses, food and all the other smells of life.