The phenomenon is one of the main mechanical defenses of the respiratory system and is usually caused by the stimulation and irritation of the nerve endings of the trigeminal.
You can sneeze due to inflammation of the nasal mucosa (a typical example is a cold), allergic reactions to some substance, sudden changes from dark to bright environments, changes in air pressure and temperature, psychological sensations or particular emotional states (such as a severe discomfort or sexual arousal).
and the mouth. As a rule, sneezing is a reaction to a small, potentially pathogenic or irritating foreign body in order to clear it from the airways. A sneeze forcibly expels air from the mouth and nose in an involuntary, spasmodic, explosive action, allowing mucus to escape.
How does a sneeze work?
The lungs store a large volume of air with a deep inhalation, while the contraction of the muscles of the chest, pharynx and larynx is coordinated. For a moment, the airways become blocked and the heart rate increases. When the air pressure in the lungs becomes too high, the muscles relax quickly and the airways open. The air is forced out of the lungs.
In addition to the mass of air, the liquids and corpuscles contained in the upper respiratory tract are also brought outside, in a sort of aerosol, consisting of thousands of droplets of mucus (flügge) for each sneeze.
Can you sneeze in your sleep?
Theoretically, sneezing cannot occur during sleep due to REM atony, a body state in which motor neurons are not stimulated and reflex signals are not transmitted to the brain. Sufficient external stimuli, however, can induce conscious awakening. the effort and violence of the act. Therefore, any sneezing that would subsequently occur would take place in a waking state.
eye. Inside the nasal cavities there are the sensory fibers of the trigeminal nerve which, if stimulated by foreign particles or other stimuli, are activated and transmit an electrical signal to the respiratory center located in the brain. At this last level, the impulses trigger a reflex. semi-autonomous (ie it does not totally depend on our will) which induce, in the opposite direction, the motor response, with the impulse to contract all the tissues of the airways and to expel the air contained in the lungs, with a significant increase in pressure internal airway. The latter accelerates and is conveyed into the nose, where it violently invests the irritating or pathogenic particles (dust, viruses, bacteria, pollen and other intruders) which leave the organism at speeds close to 160 km per hour, wrapped in protective mucus. Sneezing thus guarantees "efficient protection of the respiratory system from external threats."
In the first instance, therefore, sneezing represents a defense mechanism to eliminate pathogens or small foreign bodies, such as dust or pollen, as quickly as possible. Sneezing is usually related to a state of inflammation of the nasal mucosa (a condition typically found in colds). However, you can also sneeze due to an allergic reaction or inhalation of dust, pepper, ammonia and other irritants. In addition, consecutive sneezing can occur from exposure of the eyes, especially if inflamed, to a source of light. intense, like the sun.
Sneezing: what diseases can it be a symptom of?
The pathological and non pathological conditions that can be at the origin of the sneeze are different.
The most common are:
- Cold;
- Influence;
- Sinusitis;
- Vasomotor rhinitis;
- Respiratory allergies;
- Nasal polyposis.
In some cases, sneezing can also be induced by:
- Exposure to sunlight or sudden changes from dark to very bright environments;
- Changes in air pressure;
- Particular emotional or psychological states (e.g. severe discomfort, anxiety, sexual arousal).
Why do you sneeze when looking at the sun?
The so-called photoptarmosis (also known as photic reflex sneezing) does not have an "etiology universally shared in the scientific world. Four theories so far hypothesized are:
- Exposure to intense light would activate a part of the parasympathetic nervous system, responsible for involuntary actions, in the same way as frowning and dilating the pupils. The sneeze would be, in practice, another spontaneous reflex aroused by the sun.
- The brain may misinterpret the light stimulus as a nose irritant and respond accordingly. The cause would be, in this case, an "interference between the optic nerve and the trigeminal nerve, which controls some facial movements and is responsible for the sneeze reflex.
- The reaction of some people would depend on the greater susceptibility of the visual cortex to light.
- In the past, the reflex was likely an advantage, so sneezing in the light would be an evolutionary leftover.
Sneezing: what does it have to do with sexuality
- Some people may sneeze during the early stages of sexual arousal. The phenomenon could result from a case of abnormal interpretation in the autonomic nervous system, which regulates a number of functions in the body, including the "awakening" of the genitals during arousal.
- The nose, like the genitals, contains erectile tissue. This phenomenon can prepare the vomeronasal organ for a greater detection of pheromones.
- A sneeze has also been compared to an orgasm: tingling, body stretching, tension and release are involved in both phenomena. The endorphins then released would induce a reward system in the brain: after the sneeze a sensation of pleasure would take over.
Other manifestations are related to specific causes such as:
- Cold: feeling of exhaustion, headache and cough;
- Allergies: stuffy or runny nose, conjunctivitis, etc.
What we risk when we hold back a sneeze
Sneezing leads to a significant increase in pressure in the lungs that must be vented somewhere. If the instinct to sneeze is controlled in some way, the pressure of the air exiting the respiratory shaft could cause some problems, including:
- Rupture of capillaries of the eyes;
- Injury to the middle and inner ear;
- Laceration of an eardrum, the thin membrane located at the end of the external auditory canal
- Rupture of the pharynx (very rare);
- Aneurysm (dilation of a vascular segment with the risk of its rupture).
Although unusual and rare, similar occurrences are possible and in order not to incur it it is advisable to resist the temptation to hold back the sneeze, closing the mouth or plugging the nostrils.
, if they carry the causative agents of diseases, such as the flu or the cold.To limit the spread of these droplets in the air, when a sneeze occurs it is a good habit to put your hands (then to be washed), the forearm or a handkerchief to cover the mouth and nose.
Why do you say "Health" after a sneeze?
The habit of answering "Health!" After a sneeze seems to date back to the Middle Ages, a period in which the black plague was particularly widespread: sneezing was one of the first symptoms of the disease, so it was used to wish you hadn't contracted it.
Modern etiquette dictates that anyone who sneezes in public should apologize; reply with "Salute!" it is, on the other hand, not very indicated since the voice call would focus even more the attention of those present on the person, potentially embarrassing him.
for headaches or decongestant sprays to decrease nasal congestion.
Sneezing in case of allergies
As for allergies, for example, it is possible to limit burst sneezing and other symptoms (itching, nasal congestion, etc.) by taking antihistamines that act by counteracting the formation of histamine, produced by the immune system and active during reaction. Alternatively, to relieve the symptoms associated with inflammation of the upper respiratory tract secondary to respiratory allergy, the doctor may also indicate the use of local corticosteroids (nasal sprays), decongestants, antileukotrienes and immunotherapy (desensitization treatment against of the allergen in question). At the same time, the removal of allergens (for example: dust) from closed places where you sleep and stay can help.
