View source for Uvula

{{Short description|Fleshy appendage that hangs from the back of the palate}}
{{other uses|Uvula of cerebellum|Uvula of urinary bladder}}
{{Infobox anatomy
| Name        = Uvula
| Latin       = uvula palatina
| Image       = File:LuettePalatineUvula.svg
| Caption     = Mouth of a child showing the uvula and swollen tonsils
| Width       = 
| Precursor   = 
| System      = 
| Location    = [[Human mouth]]
| Artery      = 
| Pronunciation = {{IPAc-en|ˈ|juː|v|j|ʊ|l|ə|audio=en-au-uvula.ogg}}
| Vein        = 
| Nerve       = 
| Lymph       = 
}}
The '''uvula''' ({{plural form}}: '''uvulas''' or '''uvulae'''), also known as the '''palatine uvula''' or '''staphyle''', is a conic projection from the back edge of the middle of the [[soft palate]], composed of [[connective tissue]] containing a number of [[alveolar gland|racemose glands]], and some muscular fibers.<ref>{{cite web| url=http://www.emedicine.com/asp/dictionary.asp?exact=Y&keyword=palatine+uvula| title=eMedicine Definition| access-date=2008-05-03| archive-url=https://web.archive.org/web/20080216000915/http://www.emedicine.com/asp/dictionary.asp?exact=Y| archive-date=2008-02-16| url-status=dead}}</ref><ref>Ten Cate's Oral Histology, Nanci, Elsevier, 2007, page 321</ref> It also contains many [[serous gland]]s, which produce thin saliva.<ref name="Nadig">{{cite journal|last1=Back|first1=GW|last2=Nadig|first2=S|last3=Uppal|first3=S|last4=Coatesworth|first4=AP|title=Why do we have a uvula?: literature review and a new theory.|journal=Clinical Otolaryngology and Allied Sciences|date=December 2004|volume=29|issue=6|pages=689–93|pmid=15533161|doi=10.1111/j.1365-2273.2004.00886.x}}</ref> It is only found in [[human]]s.<ref name="UvulaOrigin">{{cite journal |vauthors=Finkelstein Y, Meshorer A, Talmi Y, Zohar Y, Brenner J, Gal R | title = The riddle of the uvula. | journal = Otolaryngol Head Neck Surg | volume = 107 | issue = 3 | pages = 444–50 | year = 1992 | pmid = 1408233 | doi = 10.1177/019459989210700318| s2cid = 25135787 }}</ref>

==Structure==

===Muscle ===
{{Main articles|Musculus uvulae}}
The muscular part of the uvula ({{Langx|la|musculus uvulae}}) shortens and broadens the uvula. This changes the contour of the posterior part of the soft palate. This change in contour allows the soft palate to adapt closely to the posterior [[pharynx|pharyngeal]] wall to help close the [[Pharynx#Nasopharynx|nasopharynx]] during swallowing.<ref>Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 108</ref>

Its muscles are controlled  by the [[pharyngeal branch of vagus nerve|pharyngeal branch]] of the [[vagus nerve]].

===Variation===
<!-- [[Bifurcated uvula]] redirects here -->
[[Image:Tanya Uvula.jpg|thumb|right|The bifid uvula of a 24-year-old woman]]
A bifid or [[wikt:bifurcation|bifurcated]] uvula is a split or cleft uvula. Newborns with [[cleft lip and palate|cleft palate]] often also have a split uvula. The bifid uvula results from incomplete fusion of the palatine shelves but it is considered only a slight form of clefting. Bifid uvulas have less muscle in them than a normal uvula, which may cause recurring problems with middle ear infections. While swallowing, the soft palate is pushed backwards, preventing food and drink from entering the nasal cavity. When the soft palate fails to close against the back of the throat during swallowing, food and liquid may pass into the nasal cavity.<ref>{{cite web |url=http://health.ivillage.com/dental/0,,6hlv,00.html |title=Split Uvula: Is It a Problem? |access-date=23 September 2007 |archive-date=14 October 2007 |archive-url=https://web.archive.org/web/20071014220221/http://health.ivillage.com/dental/0,,6hlv,00.html |url-status=dead }}</ref> Splitting of the uvula occurs infrequently but is the most common form of mouth and nose area cleavage among newborns. Bifid uvula occurs in about 2% of the general population,<ref>{{cite news | url=http://www.cnn.com/2010/HEALTH/expert.q.a/04/12/bifid.uvula.shu/index.html | title=Will a bifid uvula cause any problems? | publisher=[[CNN]] | first=Jennifer | last=Shu, M.D. | date=April 12, 2010 | access-date=2010-08-07}}</ref> although some populations may have a high incidence, such as [[Indigenous peoples of the Americas|Native Americans]] who have a 10% rate.<ref>{{cite book | title=Oski's pediatrics: principles & practice | first=Julia A. | last=McMillan |author2=Feigin, Ralph D. |author3=DeAngelis, Catherine |author4= Jones, M. Douglas | edition=4th | publisher=Lippincott Williams & Wilkins | year=2006 | isbn=978-0-7817-3894-1 | page=469 | url=https://books.google.com/books?id=VbjFQiz8aR0C&q=bifid+uvula+native+americans&pg=RA1-PA469}}</ref>

Bifid uvula is a common symptom of the rare genetic syndrome [[Loeys–Dietz syndrome]],<ref>{{cite web |url=http://www.loeysdietz.org/medical.php |title=Loeys-Dietz Syndrom Foundation |access-date=25 March 2010 |archive-url=https://archive.today/20120805012226/http://www.loeysdietz.org/medical.php |archive-date=5 August 2012 |url-status=dead }}</ref> which is associated with an increased risk of aortic aneurysm.<ref>{{cite journal |title=Bifid Uvula and Aortic Aneurysm |journal=New England Journal of Medicine |volume=359 |issue=2 |pages=e2 |doi=10.1056/NEJMicm070582 |pmid=18614778 |year=2008 |last1=Vilacosta |first1=Isidre |last2=Godoy |first2=Victoria Cañadas }}</ref>

==Function==
During swallowing, the soft palate and the uvula move together to close off the [[nasopharynx]], and prevent food from entering the [[nasal cavity]].

It has also been proposed that the abundant amount of thin saliva produced by the uvula serves to keep the throat well lubricated.<ref name= Nadig/>

It has a function in speech as well. In many languages, a range of consonant sounds, known as [[uvular consonant]]s, are articulated by creating a constriction of airflow between the uvula and the back of the tongue. The [[voiced uvular trill]], written {{IPA|[ʀ]}} in the [[International Phonetic Alphabet]], is one example; it is used in [[French language|French]], [[Arabic]] and [[Hebrew]], among other languages. It has been suggested that the uvula is an accessory speech organ.<ref name="UvulaOrigin"/>

Stimulation of the uvula also causes the [[gag reflex]] to initiate. This is often a problem for people with [[uvula piercing]]s, and a common method of inducing vomiting.{{Citation needed|date=August 2019}}
It also acts as a food sensor/guard that aids in breathing between mouthfuls, stopping small pieces of food from being inhaled, leading to choking.

==Clinical significance==

===Inflammation===
[[File:Swollen Uvula.jpg|thumb|340x340px|A swollen uvula with additional upper mouth ulcer in a run-down adult (common cold)]]
At times, the [[mucous membrane]] around the uvula may [[Swelling (medical)|swell]], causing the uvula to expand 3–5 times its normal size. This condition is known as uvulitis. When the uvula touches the throat or tongue, it can cause sensations like gagging or choking, although there is no foreign matter present.  This can cause problems with breathing, talking, and eating.

There are many theories about what causes the uvula to swell, including [[dehydration]] (e.g. from arid weather); excessive [[tobacco smoking|smoking]] or other inhaled irritants; [[snoring]]; [[allergic reaction]]; or a [[virus|viral]] or [[bacterial infection]]. An [[aphthous ulcer]] which has formed on the uvula can also cause swelling and discomfort.<ref>{{cite journal|vauthors=Biblo LA, Gilbert IA|date=May 1983|title=Aphthous ulcer of the uvula and the painful burp|journal=N. Engl. J. Med.|volume=308|issue=19|pages=1168|doi=10.1056/NEJM198305123081922|pmid=6835348}}</ref>

If the swelling is caused by dehydration, drinking fluids may improve the condition. If the cause is a bacterial infection, [[gargling]] salt water may help.  However, it can also be a sign of other problems.  Some people with a history of recurring uvulitis carry an [[epinephrine autoinjector]] to counteract symptoms of an attack. A swollen uvula is not normally life-threatening and subsides in a short time, typically within a day.

===Snoring and sleep apnea===
The uvula can also contribute to [[snoring]] or heavy breathing during sleep; having an elongated uvula can cause vibrations that lead to snoring. In some cases this can lead to [[sleep apnea]], which may be treated by removal of the uvula or part of it if necessary, an operation known as [[uvulopalatopharyngoplasty]] (commonly referred to as UPPP, or UP3). However, this operation can also cause sleep apnea if [[scar]] tissue forms and the airspace in the velopharynx is decreased. The success of UPPP as a treatment for sleep apnea is unknown, but some research has shown 40–60% effectiveness in reducing symptoms.<ref name="upppstat">{{cite web
  | last = Lehnert
  | first = Paul
  | title = Uvulopalatopharyngoplasty for obstructive sleep apnea
  | date = 3 August 2005
  | url = http://www.webmd.com/hw/sleep_disorders/hw48958.asp#ug3207
  | access-date = 26 October 2006 }}</ref>  Typically apnea subsides for the short term, but returns over the medium to long term, and sometimes is worse than it was before the UPPP.{{Citation needed|date=September 2020}}

===Velopharyngeal insufficiency===
In a small number of people, the uvula does not close properly against the back of the throat, causing a condition known as [[velopharyngeal insufficiency]]. This causes "nasal" (or more properly "hyper-nasal") speech, where extra air comes down the nose, and the speaker is unable to say certain consonants, such as pronouncing {{IPAblink|b}} like {{IPAblink|m}}.

===Nasal regurgitation===
During swallowing, the soft palate and the uvula move superiorly to close off the [[nasopharynx]], preventing food from entering the [[nasal cavity]]. When this process fails, the result is called ''nasal regurgitation''. It is common in people with [[Velopharyngeal insufficiency|VPI]], the [[Myositis|myositides]], and [[neuromuscular disease]]. Regurgitation of fluids in this way may also occur if a particularly high volume of liquid is regurgitated, or during vigorous coughing, for example being caused by the accidental inhalation of water.  Due to the action of coughing preventing the uvula from blocking the nasopharynx, liquid may be expelled back through the nose.

==Society and culture==
[[Image:Swollenuvula.jpg|thumb|right|A child's swollen uvula with [[tonsils]] ]]In some parts of Africa, including [[Somalia]], [[Ethiopia]] and [[Eritrea]], the uvula or a section of it is ritually removed by a traditional healer.<ref>[https://web.archive.org/web/20030724213921/http://www3.baylor.edu/~Charles_Kemp/ethiopian_refugees.htm Ethiopian Refugees<!-- Bot generated title -->]</ref> In this case, the uvula may be noticeably shortened. It is not thought to contribute to [[velopharyngeal inadequacy]], except in cases where the tonsils have also been removed.<ref>{{cite journal |vauthors=Hartley B, Rowe-Jones J | title = Uvulectomy to prevent throat infections. | journal = J Laryngol Otol | volume = 108 | issue = 1 | pages = 65–6 | year = 1994 | pmid = 8133174 | doi=10.1017/s0022215100125873}}</ref>

==History==

===Etymology===
In Latin, ''[[wikt:uvula#Latin|ūvula]]'' means "little grape", the diminutive form of ''[[Wiktionary:uva#Latin|ūva]]'' "grape" (of unknown origin). A swollen uvula was called ''ūva''.<ref>{{cite book |title=The American Heritage Dictionary of the English Language |url=https://archive.org/details/americanheritage0000unse_a1o7 |url-access=registration |edition=4th |year=2000 |publisher=Houghton Mifflin |location=Boston |isbn=978-0618082308 |page=[https://archive.org/details/americanheritage0000unse_a1o7/page/1896 1896]}}</ref>

==See also==
{{Anatomy-terms}}
*[[Epiglottis]]
*[[Tonsil]]
*[[Uvula (disambiguation)]]

==References==
{{Reflist|30em}}

== External links ==
{{Commons}}
* {{MedlinePlusEncyclopedia|001257}} - Uvulitis

{{Mouth anatomy}}
{{Authority control}}

{{DEFAULTSORT:Palatine Uvula}}
[[Category:Palate]]
[[Category:Human throat]]
[[Category:Speech organs]]