Sneezing - is a reflex intended to protect the respiratory tract from irritants.A sharp exhalation occurring when sneezing, helps cleanse the upper airways.Through the nose air enters the respiratory system.Nasal cavity acts as a filter to prevent ingress of dust and coarse particles to the lungs, and warming the inhaled air to body temperature.The first signs of sneezing, runny nose - that it can be?
Sneezing is a protective reflex of the body and is accompanied by a sudden intense unconscious discharge of air through the nose and mouth.Its role is primarily to protect the respiratory tract from the irritating particles whose introduction into the respiratory system may cause them significant harm.Sneezing is also used to remove accumulated nasal mucus and foreign bodies, preventing it from clogging.When sneezing stream of pressurized air is ejected from the lungs to the outside through the respiratory tract.Most of it comes out through the mouth, but some residue redirected soft palate and pulled out
sneezing and runny nose, is thrown up to 5,000 droplets of liquid that can be infected and can extend to a distance of 3.7 meters from nose.While the first sign that sneezing can be a classic symptom of the common cold, which is often accompanied by a viral infection of the respiratory tract, there are many factors that trigger this reflex reaction.The most common ones are:
- inhalation of small particles from the air such as dust, smoke, aerosols;
- allergic reaction to mold, provoked by the inhalation of airborne spores;
- inhalation of particles of the epidermis, including the head (dandruff), both human and animal;
- allergy to pollen (hay fever) and house dust mite;
- upper respiratory tract infection;
- nasal polyps;
- eye irritation bright light;
- change of ambient temperature;
- inhalation of cocaine.
first symptoms of sneezing, runny nose, cough and what is the role of sneezing occurs upon stimulation of the sensory nerve endings, which are located deep in the mucosa of the nasal cavity, such as by inhalation of dust.He was often at the first sign of a cold is preceded by tickling sensation in the nose.This is followed by a reflex reaction, which results in the enhanced production of watery mucus secretory cells (sneezing can occur when dry nose).
In response, the brain generated by motor nerve impulses coming to the respiratory muscles, causing their decline.Thus, it carried out a deep breath, airway closure and compression of the chest, followed by vigorous rapid exhalation.The air escapes from the lung upward and outward, carrying excess secretions and trapped particles in it, and out through the nose and mouth.This process occurs spontaneously and can not be volitional control.
Approximately 25% of the people at the first sign of sneezing, runny nose eye irritation occurs when a bright light such as the sun.This phenomenon is known for several decades, and is often referred to as a light ptarmic reflex.The exact cause is unknown.However, perhaps this reaction is due to the intersection of reflex pathways in the brain.The normal reflex arcs are on separate paths of the nervous system.In the case of the light reflex ptarmic possible that nerve impulses are crossed at the level of neural circuits ocular reflex to light and ptarmic reflex.As a result, while there is constriction of the pupil and sneezing.Light ptarmic reflex does not bear any protective function and, apparently, is rudimentary (not necessary) the first sign of evolution, sneezing, runny nose.Other factors, inexplicably capable of causing sneezing, include combing the hair, plucking eyebrows and scratching the inner corner of the eye.