Why do we sneeze

Did you know that when we sneeze we tend to expel the air at a speed greater than 150 kilometers per hour? In fact, most experts consider that, approximately, the air that we expel through a sneeze does so at an average speed of between 110 and 160 kilometers per hour. And, indeed, as happens with mucus and mucus (as we saw in Why the mucus appear), sneezing is also a defense mechanism of our respiratory system.

Explained more or less simply, we can say that a sneeze is a reflex, convulsive, expulsion of air from the lungs mainly through the nose, although eventually we can also do it through the mouth.

How sneezing occurs

Sneezing is mainly produced and especially by the irritation, which stimulates the sensitivity of the nose, which causes a strong and rapid inhalation of air, which passes to the lungs, at which time the various abdominal muscles make the diaphragm rise suddenly in order to increase the pressure in the lungs, at the same time that the muscles of the pharynx open and close. It is at this moment when the air is released by the nose, and eventually by the mouth.

It is also normal that when we sneeze we can not keep our eyes open. It is a natural reflection of our body to prevent our eyes from being damaged when the air goes from the lungs to the nose and increases the pressure of the eyes, and as a way to prevent the germs that we find in the saliva, and that fly out with the sneeze, touch the eyeball and may cause an infection.

Why sneezing occurs

Taking into account that sneezing is a defense mechanism of our respiratory system, and that in reality it is a natural reflex, we can investigate and discover more about why sneezing occurs, why it appears:

  • Colds, flu and colds: is one of the most common causes, as our nose tends to fill with excessive mucus, which causes the air can not be filtered normally, finally triggering the sneeze.
  • Allergic reactions: it is another of the most common causes. In this case, our body reacts to an element to which it is allergic, for example the pollen of a flower when inhaled, which produces sneezing.

As we see, it is a natural mechanism of perfect defense, which our respiratory system 'uses' in order to expel pernicious substances. And to do so with the help of a large jet of air pressure, which expel through the nostrils at very high speed.

Images | vika mno / Matt Batchelor

Operation Ouch - Sneezing | Biology Facts for Kids (February 2021)