Nose: facts, functions and diseases (2023)

The human nose is more than just a flap of flesh and cartilage at the front of the face. In addition to being part of the respiratory system that breathes in oxygen and exhales carbon dioxide, the nose also contributes to other important functions such as hearing and taste.

size and shape

Human noses can come in a variety of shapes and sizes due to genetics and injury.Men generally have larger noses.than women, the researchers say. According toGuinness Book of Records, the largest living human nose belongs to Mehmet Ozyurek of Turkey. Its nose is 8.8 centimeters long from the bridge of the nose to the tip.

function

The two openings in the nose are called the nostrils or nape. They lead to two nasal cavities separated by the septum, a cartilage wall. Inside the face is an intricate system of ducts and air pockets called sinuses. The sinuses extend to the back of the skull, just above the oral cavity, in the cheekbones, and between the eyes and eyebrows. All of these areas are at least partially responsible for breathing, smell, taste, and immune system defenses.

The human nose can smell more than 1 trillion smells,according to researchers. The nose smells with the olfactory cleft, which is the roof of the nasal cavity. It's right next to the "olfactory" part of the brain, which consists of the olfactory bulb and fossa. This part of the nose has many nerve endings that transmit olfactory sensations to the brainAmerican Society of Rhinology.

The nasal passages on either side of the nose open into the choanae and then into a chamber called the nasopharynx, the upper part of the throat. This chamber opens into the oropharynx, the area of ​​the throat behind the mouth. When air is inhaled through the nostrils, it travels through the nasal passages, choanae, nasopharynx, oropharynx, and larynx, and finally reaches the lungs. Basically inrespiratory system, the nose is a passage for air.

Snot and snot

The nose is also the first line of defense against disease. The nose is lined with fine, hair-like protrusions known as cilia. The sinuses are lined with mucus-producing cells. The mucus (or "phlegm") keeps the nose from drying out. Together, the cilia and mucus collect dust, bacteria, and other debris before they can get to the rest of the bodyBritannica-Enzyklopädie. [Infographic: What Your Slime Says About You]

Nasal mucus, which is made up of water, proteins, antibodies, and salts, is usually clear. But during an infectionSlime can turn yellow or green, indicating that the body is fighting a bacterial or viral infection. The green color comes from a chemical secreted by white blood cells, specifically the heme in the iron-containing enzyme myeloperoxidase, to kill pathogens.

Clumps of dried mucus, dirt, and debris are called "snot," and despite the taboo, a Canadian scientist thinks "nose picking" and eating snot can be good for you.

Scott Napper, a professor of biochemistry at the University of Saskatchewan, hypothesizes that snot tastes sweet for a reason (believe his word or try it yourself). That can be a signal for the body to eat it and get immune-boosting benefits.

"Could there be a way to teach your immune system about your environment by consuming these mucus-trapped pathogens?" Napper said soCanadian Broadcasting Corporation.

Their hypothesis fits other theories about the link between better hygiene and increases in allergies and autoimmune diseases, he said. "From an evolutionary perspective, we evolved in very dirty conditions, and perhaps this desire to keep our environment and behavior sterile isn't really in our best interest."

other senses

Without the nose, the body could not taste the food as well. What people call "taste" is actually a mixture of different sensations. One of the sensations is smell. When food is ingested, the nose smells the food and sends information to the mouth in a process called olfactory referencing. Because of this, people with a cold or other nasal ailment find food tasteless.

The nose also plays a role in hearing. The nasopharynx is flanked on both sides by the Eustachian tubes. These tubes connect the nasopharynx to the middle ear. The nasopharynx fills the middle ear with air and equalizes the air pressure in the ear with the surrounding atmosphere, which the American Rhinological Society says is an important part of hearing properly.

diseases and conditions

Because the nose is complex, there are many things that can go wrong. “The most common complaints that people come to our practice with are nasal breathing difficulties, nasal congestion, nasal allergies, chronic sinus infections and nasal polyps. Another thing we see more often is people coming to us with a poor sense of smell," said Dr. Seth J. Kanowitz, attending physician in the Department of Otorhinolaryngology at Morristown Medical Center in Morristown, NJ, and co-director of the hospital's Cranial Otorhinolaryngology Program.

The most common cause of smell loss is a viral infection like the common cold, Kanowitz told Live Science. Sinus infections, nasal polyps, tobacco use, head injuries, and in extremely rare cases, tumors can also lead to loss of smell. Some loss of smell also occurs during the natural aging process, similar to vision and hearing loss.

Sinusitis is another common nasal disease. "Sinusitis is a condition that means inflammation of the sinuses," said Dr. Rob Straisfield, MJ Wellness Medical Associate, to Live Science. Inflammation can result from allergies, viruses, and certain diseases. Some symptoms include weakness, fever, fatigue, cough, and constipation, depending on the caseUS National Library of Medicine(NLM).

The nasal septum, the flat sheet of cartilage in the middle of the nose, can become damaged and displaced to the left or right, or the nose can grow crooked. This condition is called a deviated septum. A deviated septum can cause breathing problems and discomfort because one or both nasal chambers are smaller than they should be. Sometimes a deviated septum is corrected with surgery.

Many people have problems with congested sinuses or nasal congestion. This can be caused by inflamed tissue or blocked mucus. Often these problems can be treated at home. "Saline rinses using large-capacity, low-pressure bottles have been shown to be highly effective at clearing nasal passages, removing allergens and thick mucus, and relieving sinus infections, potentially eliminating the need for antibiotics," Kanowitz said.

Things that come out of the nose can be a problem. A runny nose is caused by the production of mucus in the nose. Anything that irritates or inflames the nose, such as allergies, a cold, the flu, or dust, can trigger mucus productionThe Mayo Clinic. Nosebleeds occur when the tiny blood vessels in the nose burst due to dry air, irritants, chemicals, bumps on the nose, and various other factors.

additional resources

• NLM: Injuries and diseases of the nose
• Emory University: Nose and Mouth
• American Academy of Otolaryngology: Your Nose, the Guardian of Your Lungs