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:
1. 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.
2. 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
3. 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.
4. 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.
5. 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
6. 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.
7. 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.