Anatomy
The nasal mucosa is a thin layer of tissue that lines our nasal cavities from the inside. It is made up of certain skin cells, which have about 50 – 300 short brush-like nasal hairs, the so-called cilia. In addition, glands for secretion formation and venous plexuses for air flow regulation are embedded in the nasal mucous membrane.
The secretion formed by the glands wets the entire surface of the mucous membrane. The upper nasal passage contains about 10 million specialized sensory cells. These so-called olfactory cells form our olfactory mucosa, which is capable of perceiving odours.
Their special feature, in contrast to other sensory cells such as those of the eyes or ears, is their ability to regenerate. They are renewed by the body approximately every one to two months. In about 80% of people, the so-called nasal cycle ensures a mutual swelling and decongesting of the nasal mucous membrane via the embedded venous networks.
The consequence is that most of the time the patient breathes only through one nostril. This is due to the fact that one of the two nostrils is minimally swollen. Most of the inhaled air then flows through the open nostril. The duration of the nasal cycle varies between 30 minutes and 14 hours. It is assumed that the nasal mucous membranes regenerate and rest.
Anatomy of the nose
Function
The main functions of our nasal mucosa are smelling and breathing as well as the preparation of our breathing air by cleaning, warming and humidifying it. The nasal mucosa serves to keep our airways clean and to defend against infections. If foreign bodies, pathogens or other particles, such as dust, enter our body through the air we breathe, they adhere to the nasal mucosa to a certain extent.
The cilia of the nasal mucous membrane beat about 450 to 900 per minute and thus transport the mucus, which is contaminated with the smallest particles, in the direction of the throat. There it is either ejected through the mouth or swallowed and decomposed by the acidity of our stomach. The mucus produced by the glands prevents pathogens and dirt particles from entering our lungs.
Another function of the nasal mucosa is to warm the air we breathe in. The strong blood flow through the nasal mucosa via extensive venous plexuses warms the cold air we breathe in, thus preventing cold air from entering the bronchi and lungs. In addition, the formation of secretions by a healthy nasal mucosa and their evaporation moistens the air we breathe.
Furthermore, certain medications such as nasal sprays are absorbed through the nasal mucosa. The abuse of drugs such as cocaine is also caused by the so-called “sniffing”, i.e. by absorption into the body’s circulation through the nasal mucous membrane. In addition, our nasal mucous membrane contributes to the formation of taste, voice and speech: if you have a cold or keep your nose closed, your voice changes, but the taste of the chewed food is also largely absent.