sneeze

Article

July 6, 2022

Sneezing or sneezing is a convulsive, semi-autonomous expulsion of air from the nose and mouth. Some diseases can be transmitted by the sneeze that spreads up to 40,000 infectious droplets whose diameter varies from 0.5 to 5 µm.

Science

Cause and effect

Sneezing is usually caused by nasal irritation and sometimes a bacterial blockage in the throat, lungs, or nasal passages. Allergy-causing substances such as pollen, pepper, pet dander, dust, as well as other non-allergenic particles are generally harmless, but when they irritate the nose, the body responds by exhaling them from the nasal passages. Sneezing is the body's reaction to obstruction of the nasal passages, especially the nose and throat. Its function is to expel something that is bothering you from the body. That's why we sneeze when we're in dusty, dirty, or heavily scented environments. Another time we sneeze a lot is when we have a cold. In this case, the body uses the sneeze to remove the phlegm from the lungs from the body. The muscles of the back, abdomen, those below the ribs are involved in sneezing. When dust, smoke or smell irritates the nose, the respiratory center is informed and stops normal breathing, makes you take a deep breath, and then suddenly makes all those muscles contract, pushing all the air out at once. The glottis blocks the exit of air from the lungs, as if it were a lid on the throat and soon after they open, releasing the way.

Eyelid closing response

It is generally considered impossible for someone to keep their eyelids open during a sneeze. The eye-closing reflex is due to a non-obvious purpose: the nerves that serve the eyes and nose are close and related, and stimulation to one of them usually stimulates some response in the other. However, closing the eyes can protect the tear ducts and blood vessels from bacteria expelled in the sneeze.

Sneeze Reflex

The stimulus that initiates the sneeze reflex is irritation of the nasal passages; Afferent impulses pass through the fifth cranial nerve to the medulla, where the reflex is triggered. A series of reactions similar to the cough reflex occur: First, up to 2.5 liters are quickly inspired; Second, the epiglottis closes and the vocal cords are closed tightly to trap air inside the lungs; Third, contraction of the abdominal muscles, pressing the diaphragm, and contraction of the internal intercostals, increasing intrapulmonary pressure to 100 mmHg; Fourth, the vocal cords and epiglottis open abruptly causing the "explosion" of air to the external environment.- happens; however, that the uvula is depressed, so that large amounts of air quickly pass through the nose, thus helping to clear the nasal passages of foreign material.¹

Dangers of suppressing a sneeze

Repressing or holding back a sneeze can, especially in case of pre-existing conditions, have very serious consequences, due to the sudden increase in intracranial, intrathoracic or intra-abdominal pressure, which can cause damage to the optic nerve (glaucoma) or retina (Valsalva retinopathy). , causing headaches, eye bleeding, forcing air through the Eustachian tubes and causing rupture of the eardrum or damage to the inner ear causing vertigo or hearing loss, weakening a blood vessel in the brain and causing it to rupture (stroke), etc. reasons one should never avoid sneezing.

Sneezing while sleeping

Sneezing cannot occur during sleep due to REM sleep atony – a body state in which motor neurons are not stimulated and reflex signals are not relayed to the brain. However, enough external stimulants can cause a person to wake up from sleep to sneeze, but any sneezing that occurs afterwards would happen in a p state.