Four seas entertainment news: many people have such experience, the most obvious feature of cold is endless nasal mucus, so how is the formation of cold nasal mucus? Under normal circumstances, some biological nasal mucosa always secrete mucus to moisten the nasal membrane, wet the air inhaled, and adhere to the dust and micro dust and microorganisms inhaled by the air, which is nasal mucus.
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Causes of nasal mucus formation in cold
Under normal circumstances, the nasal mucosa of some organisms is secreting mucus from time to time to moisten the nasal membrane, moisten the inhaled air, and adhere to the dust and micro dust and microorganisms inhaled in the air, which is nasal mucus.
The inner surface of the nasal cavity of healthy people is lined with a complete layer of mucous membrane. There are many goblet cells with secreting function on it. There are mucinous glands under the nasal cavity of healthy people. They secrete water for moistening and inhaling air. In addition, the mucous glands often secrete a small amount of mucus, evenly distributed on the surface of the mucosa. Absorb dust and microorganism in the air. Mucus also contains lysozyme, which can inhibit and dissolve bacteria. This mucus is nasal mucus.
Most of the nasal mucus is secreted by the nasal mucosa itself. The nasal mucosa contains a kind of goblet cell, which makes a lot of mucin. When mucin is released to the outside of the cell, it absorbs a lot of water, which forms nasal mucus for nasal use.
Part of the snot is actually tears. These tears are produced from the lacrimal gland, part of which flows to the lacrimal canaliculi, and then to the nasal cavity through the nasolacrimal duct, becoming part of the nasal mucus.
A small part of it evaporated, a small part of it dried up and turned into snot, but most of it was swallowed by us.
Cilia grow on the mucous membrane of the nasal cavity. These cilia will swing back and forth, and the nasal mucus will be sent back to the pharynx. Because the nasal cavity and esophagus are connected, so most of the nasal mucus is unconsciously swallowed.
A healthy person's nose has to deal with hundreds of milliliters of snot every day!
Goblet cells produce a lot of mucin. When mucin is released to the outside of the cells, it absorbs a lot of water, and its volume can expand 600 times! Goblet cells only need to produce 1 ml mucin a day, which is enough to meet the normal needs of nasal cavity.
There is always snot in the nasal cavity, and it can't be separated from it.
Nasal mucus is a barrier to protect the body: it prevents the nasal mucosa from drying, so that it can moisten the inhaled air and adhere to the dust, pollen and microorganisms inhaled in the air, so as not to stimulate the respiratory tract or cause infection.
Rhinorrhea and allergic rhinitis
Allergic rhinitis is a multifactorial disease induced by the interaction between gene and environment. The risk factors of allergic rhinitis may exist in all age groups.
1. Genetic factors
Allergic rhinitis patients have atopic constitution and usually show familial aggregation. Some genes have been found to be associated with allergic rhinitis.
2. Allergen exposure
Allergens are antigens that induce and react with specific IgE antibodies. Most of them come from animals, plants, insects, fungi or occupational substances. Its components are protein or glycoprotein, and few are polysaccharides. Allergens are mainly divided into inhalation allergens and food allergens. Inhaled allergen is the main cause of allergic rhinitis.
(1) House dust mite and dust mite are the main mites in subtropical and tropical areas. House dust mites feed on human dander and mainly live in mattresses, beds, pillows, carpets, furniture and fluffy toys. It propagates fastest in hot (above 20 ℃) and humid (relative humidity > 80%). The house dust mite allergen is contained in its excreta particles, which are exposed to the air and can be deposited again soon after the contaminated fabric is touched. The concentration of mite allergen in the air is related to the incidence of allergic rhinitis.
(2) Wind borne pollen can affect people hundreds of kilometers away from the source of pollen because of its large amount of dispersal and long-distance transmission. Insect borne pollen can only be sensitized by direct contact, such as agronomists and florists. The sensitivity of pollen varies with season, geographical location, temperature and plant species. Most pollen sensitizers suffer from conjunctivitis.
(3) Animal dander the skin and secretion of animals carry allergens. Cat and dog allergens widely exist in indoor dust and furniture decoration.
(4) Allergenic fungi release allergenic spores to indoor and outdoor environment, and grow rapidly in hot and humid environment.
(5) Cockroach allergens are found in their feces and crustaceans, and the particles are large and do not spread in the air.
(6) Food allergens are rare in allergic rhinitis without other systemic symptoms. On the other hand, food allergy is common in patients with multiple organ involvement. For infants, most of them are caused by milk and soybeans; for adults, common food allergens include: peanuts, nuts, fish, eggs, milk, soybeans, apples, pears, etc.