Mucus 501188 225159156 2008-07-12T05:23:48Z VoABot II 1879647 BOT - Reverted edits by [[Special:Contributions/99.7.44.215|99.7.44.215]] {[[User:VoABot_II/Help#Revert_reasons|possible vandalism]]} ([[User:VoABot_II/Mistakes|mistake?]]) to last version by "Insanity Incarnate". {{Citations missing|date=November 2007}} [[Image:Mucus cells.png|thumb|Mucus cells.]] '''Mucus''' is a slippery secretion of the lining of the [[mucous membrane]]s in the body. It is a viscous [[colloid]] containing [[antiseptic]] enzymes (such as [[lysozyme]]) and [[immunoglobulin]]s. Mucus is produced by [[goblet cell]]s in the mucous membranes that cover the surfaces of the membranes. It is made up of [[mucins]] and inorganic salts suspended in water. [[Phlegm]] is a type of mucus that is restricted to the respiratory tract, while the term mucus refers to secretions of the [[nasal cavity|nasal]] passages as well. ==Respiratory system== In the respiratory system, mucus traps small particles such as bacteria and dust, helping to prevent them from entering the body when breathing in through the nose; this occurs especially in the nose. Mucus aids in the protection of the [[lung]]s by trapping foreign particles that enter the nose during normal breathing. Additionally, it prevents [[tissues]] from drying out. Increased mucus production in the respiratory tract is a symptom of many common illnesses, such as the [[common cold]]. The presence of mucus in the [[nose]] and [[throat]] is normal, but increased quantities can impede comfortable breathing and must be cleared by blowing the nose or [[expectoration|expectorating]] [[phlegm]] from the throat. Among the components of nasal mucus are [[tears]]. Nasal mucus is mucus produced by the nasal [[mucosa]]. It serves to protect the respiratory tract and trap foreign objects such as dust and pollen before they enter the remainder of the [[respiratory tract]]. Nasal mucus is produced continually, and most of it is swallowed unconsciously. ===Mucin === Mucus is produced by submucosal cells as well as goblet cells in the respiratory system. It consists of [[mucin]], a highly [[glycosylated]] [[peptide]]. Upon stimulation, MARPKs (myrastine-alanine rich protein kinases) signal the binding of mucin filled [[Vesicle (biology)|vesicles]] to the [[plasma membrane]]. The fusion of the vesicles causes the release of the mucin, which as it exchanges [[Calcium|Ca<sup>2+</sup>]] for [[Sodium|Na<sup>+</sup>]] expands up to 600 fold. The result is a [[viscoelastic]] product of interwoven molecules called mucus. ===Diseases involving mucus=== Generally mucus is clear and thin, serving to filter air during inhalation. During times of infection, mucus can change colour to yellow or green either as a result of trapped [[bacteria]],{{Fact|date=April 2008}} or due to the body's reaction to [[virus|viral]] infection.<ref>{{cite web | url = http://www.health.arizona.edu/health_topics/general_health/phlegm.html | title = Yellow-green Phlegm and Other Myths | accessdate = 2007-10-22 | language = english | format = html | source = University of Arizona campus health services }}</ref> Such coloured mucus or phlegm usually has an offensive putrid odour. In the case of bacterial infection, the bacterium becomes trapped in already clogged [[Paranasal sinus|sinuses]], breeding in the moist, nutrient-rich environment. [[Antibiotics]] may be used fruitfully to treat the secondary infection in these cases, but will generally not help with the original cause. In the case of a viral infection such as cold or flu, the first stage of infection causes the production of a clear, thin mucus in the nose or back of the throat. As the body begins to react to the virus (generally one to three days), mucus thickens and may turn yellow or green. In these cases, antibiotics will not be useful, and are a major source of misuse. Treatment is generally symptom-based; the only cure is to allow the immune system to fight off the virus over time. ===Cystic fibrosis=== {{main|Cystic fibrosis}} [[Cystic fibrosis]] is an inherited disease that affects the entire body, but symptoms begin mostly in the lungs with excess production of mucus which is difficult to expel. ===Cold weather and mucus=== During cold weather, the [[Cilium|cilia]] which normally sweep mucus away from the nostrils and towards the back of the throat (see [[respiratory epithelium]]) become sluggish or completely cease functioning. This results in mucus running down the nose and dripping (a runny nose). Mucus also thickens in cold weather; when an individual comes in from the cold, the mucus thaws and begins to run before the cilia begin to work again. ===As a medical symptom=== Increased mucus production in the respiratory tract is a symptom of many common diseases, such as the [[common cold]]. Nasal mucus may be removed by blowing the nose, or by using traditional methods of [[nasal irrigation]]. Excess mucus, as with a cold or [[allergies]] may be treated cautiously with [[decongestant]] drugs. Excess mucus in the bronchial tubes, as which occurs in [[asthma]] or [[bronchitis]], may be treated with anti-inflammatory drugs to reduce the mucus production. Thickening of mucus by decongestant drugs may produce problems of drainage and circumstances that promote infection. Mucus with any color other than clear or white is generally an indicator of an [[infection]] of the nasal [[mucosa]] or the [[paranasal sinus]]. ==Digestive system== In the digestive system, mucus is used as a lubricant for materials which must pass over membranes, e.g., food passing down the [[esophagus]]. A layer of mucus along the inner walls of the [[stomach]] is vital to protect the cell linings of that organ from the highly acidic environment within it. ==Reproductive system== In the female reproductive system, [[Cervix#Cervical mucus|cervical mucus]] prevents infection. The consistency of cervical mucus varies depending on the stage of a woman's menstrual cycle. At ovulation cervical mucus is clear, runny, and conducive to sperm; post-ovulation, mucus becomes thicker and is more likely to block sperm. In the male reproductive system, the [[seminal vesicles]] contribute up to 60% of the total volume of the [[semen]] and contain mucus, amino acids, and fructose as the main energy source for the sperm. ==See also== *[[Empty nose syndrome]] *[[Spinnbarkeit]] ==References== {{reflist}} [[Category:Body fluids]] [[Category:Exocrine system]] [[ay:Jurma]] [[cs:Hlen]] [[da:Slim]] [[de:Schleim]] [[et:Lima]] [[es:Moco]] [[fr:Mucus]] [[id:Ingus]] [[it:Muco]] [[he:ריר]] [[la:Mucus]] [[lt:Gleivės]] [[nl:Slijm]] [[ja:粘液]] [[no:Snørr]] [[pl:Śluz]] [[pt:Muco]] [[scn:Mòccaru]] [[fi:Räkä]] [[sv:Slem]] [[tl:Kulangot]] [[ta:மூக்குச்சளி]] [[yi:שליים]] [[zh:黏液]]