Contributor: Michael Benninger, MD
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Our noses, along with our eyes and mouths, are the facial points of our appearance and – in many ways – our identity. The nose is prominently visible from the front and side, and in many cases, we can determine ethnicity from the size and shape of the nose. The critical life functions that our facial organs perform may seem pretty obvious. Yet, when it comes to the nose, there is more than meets the eye.
Here are seven surprising facts about your nose:
- Your nose is the main route for breathing
The nose and mouth can serve as the pathway of air entering and exiting the lungs. In normal breathing, the nose is the primary pathway. Even with aggressive exercise where mouth breathing becomes dominant, some air continues to pass through the nose. Despite the fact that the mouth is a bigger tube, people feel remarkably uncomfortable if their noses are plugged or congested.
This nasal breathing role is critical in newborns, who must breathe through their noses almost all the time. This is a unique feature related to the configuration of their throats that allow them to breathe and suckle at the same time without choking. This cannot happen in older children or adults who have to stop breathing to swallow.
The nose plays another important role in breathing. There is a reflex neural mechanism that connects the nose to the lungs, called the nasal-pulmonary reflex. As the nose closes up, the lungs become more closed, and as the nose opens up, the lungs open up. Although it is difficult to know how big a factor this is, it may be important when there is difficulty breathing or when there is a high volume of breathing with exercise. This may be why some elite athletes use nasal strips to open their noses during exercise.
- Your nose humidifies the air you breathe
The nose processes the air we breathe to prepare it for our lungs and throat, which do not tolerate dry air well. As the inhaled air passes through the nose, it is moisturized and humidified, thanks to a complex multiple layer structure called turbinates.
Now you know why your throat feels dry when you’ve been breathing a long time through the mouth: The inhaled air didn’t get humidified in the nose.
- Your nose cleans the air you breathe
The air we breathe has all kinds of stuff in it – from oxygen and nitrogen to dust, pollution, allergens, smoke, bacteria, viruses, small bugs and countless other things. The nose helps clean that air. On the surface of the nasal tissues, particularly the turbinates, are cells with small hair-like appendages called cilia that trap much of the bad stuff. Once captured, the bad stuff sits in the mucous and gradually is pushed into the throat, where it’s swallowed. Our stomachs tolerate bad stuff much better than our lungs.
- Your nose regulates the temperature of the air your breathe
Just like our throat and lungs do not like dirty air, they do not like air that is too cold or too hot. The passing of the air through the nose allows the air to become more like body temperature, which is much better tolerated by the tissues. Warming cool air is more common than cooling warm air, as humans spend much more of their time in environments below body temperature — 98.6 degrees — than above it. One clear manifestation of the warming and humidifying effect is the runny nose we get in cold weather, which is related to condensation of the moisture in the nose when exposed to cold air.
- Your nose protects you
High in the nose are a large number of nerve cells that detect odors. To smell, the air we breathe needs to be pulled high in the nose so that it can come in contact with these nerves. When we have a cold or allergies, it’s hard for the air to get to these receptors and so people notice a decreased ability to smell.
Smell plays a key role in taste. We have four primary tastes: bitter, sour, sweet and salty. All of the refinements in taste are in fact related to smell, so people feel that food is tasteless when their ability to smell is decreased.
The sense of smell is not only for pleasure; it is necessary for safety. We need our smell to detect smoke, spoiled food and some toxic gases. People who have lost their sense of smell need to have alarms for these gases and they have to be careful with what they eat.
Lastly, smell may be important in identification. Many people can identify those close to them by their smell, whether that’s through their characteristic lotion or perfume or their characteristic body odor.
- Your nose shapes the sound of your voice
What we hear when people speak and sing is in large part related to the resonating structures of the throat and nose. The voice is produced in the larynx but that sound is really a buzzing sound. The richness of the sound is determined by how the sound is processed above the larynx, which occurs in the nose and throat. It’s the same principle that separates a grand piano from a child’s toy piano. The nasal voice we hear in someone with a cold and allergies is due to the loss of this nasal resonation since the air cannot pass through the nose.
It’s very hard to talk about the nose without mentioning the sinuses, which have a number of important and positive roles. The sinuses are air-filled structures in the head that make the head lighter and probably played an important role in allowing us to become upright. They also serve as air cushion shock absorbers that help protect the brain and eyes.
Sinuses are part of voice resonance. Sinuses also help control the amount of nitric oxide in the body and in the lungs. Although the potential value of nitric oxide would take an entire article to describe, it appears that it plays positive roles in breathing and potentially in immune function.
- Your nose helps you find a mate
It’s amazing how many of our body functions are directed toward sexual activity and reproduction. The nose plays a critical role in our perceptions of sex through the olfactory system. The sense of smell is a key component of how we identify people when we are close to them. The characteristic smell of a person’s perfume or cologne or the scent of their shampoo or soap may be important to sexual arousal. The smell of human perspiration has a direct effect on sexual receptors in the brain. Loss of smell correlates with decreased sexual drive.
Another interesting and widely debated area is the impact of pheromones, which are very important to reproduction in animals, as well as on human sexuality and stimulation. Particularly fascinating is a small accessory organ in the nose – the vomeronasal organ (VNO) – that is related to the olfactory system. Some refer to it as the sixth sense. The VNO is located at the base of the nasal septum or in the roof of the mouth and is present in almost all animals, including amphibians. Unlike in many animals like rodents and dogs where the VNO is important, the human VNO is largely vestigial, which means it’s non-functional or acts as an old remnant like the appendix. But some researchers believe that it still plays a role in pheromone and other chemical communication.
Most of us ignore our nose unless it gives us trouble, but clearly it’s one of the most versatile and elegant organs in the human body.
This post is based on one of a series of articles produced by U.S. News & World Report in association with the medical experts at Cleveland Clinic.