The Nose
 Know your nose
 Functions of the nose
 Nasal Dysfunctions
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Know your nose

The nasal cavity is divided into two passages by the nasal septum. The nasal septum is composed of both bone and cartilage and extends from the nostrils to the back of the throat. Bones called nasal conchae project into the lateral walls of the nasal cavity, forming a series of folds called turbinates. There are three turbinates on each side of the nasal cavity and are lined by a thick mucous membrane. Turbinates greatly increase the surface area of the nasal cavity. During inhalation air is directed over and under the turbinates.

Lining the nasal cavity is a mucous membrane rich with blood vessels. As air passes over the nasal mucosa it is prepared and conditioned to safely pass deeper into the respiratory system and ultimately end up in the lungs.

The heat radiated from the blood vessels warms the air to near body temperature. Simultaneously, watery mucous is secreted humidifying the air and trapping foreign particles. The increased surface area provided by the turbinates aids this processes to be performed quickly.

Cells in the mucous membrane have tiny hair-like projections called cilia. Usually, the mucus traps incoming dirt particles, which are then moved by the cilia; in coordinated waves, they sweep a layer of mucus to the back of the nose every 5-8 minutes. The mucus then moves toward the front of the nose or slips into the throat where it is swallowed, rather than inhaled into the lungs. The acid of the stomach destroys the harmful nasal debris.

Unfortunately, there are some conditions that cause the cilia to stop working. The cilia can be paralyzed most of all by infection but also by factors such as cold temperatures, cigarette smoke, some medications (e.g. antihistamines), or by excess dryness. When the cilia do not work well, we have trouble with nasal crusting and sinus infections. It has been demonstrated by numerous scientific studies that cilary activity can be improved by salty water.

DID YOU KNOW: the cilia in our noses beat 400-800 times each minute!

The nasal mucosa which lines the roof of the nasal cavity and the superior turbinates is structurally modified to detect odor-producing chemicals. On its surface layer, are millions of specialized nerve cells called olfactory (nasal) receptors.

Several open air-filled chambers called paranasal sinuses (Frontal, Ethmoid, Maxillary) are present in the bones surrounding the nasal cavity. The air-filled sinuses help lighten the skull and resonate the voice sounds. Like the nasal cavity, the sinuses are lined with a mucous membrane composed of cells that produce mucus and have cilia. Incoming dirt particles are trapped by the mucus, and then moved by the cilia into the nasal cavity, through small sinus openings. Because these openings are so small, the drainage can easily be blocked by conditions such as colds or allergies, which produce swelling of the mucous membranes. Blockage of normal sinus drainage leads to sinus inflammation and infection (sinusitis).