| Uvula | |
|---|---|
 Mouth of a child showing the uvula and swollen tonsils | |
| Details | |
| Pronunciation | /ˈjuːvjʊlə/ ⓘ |
| Location | Human mouth |
| Identifiers | |
| Latin | uvula palatina |
| MeSH | D014609 |
| TA98 | A05.2.01.004 |
| TA2 | 2781 |
| FMA | 55022 |
| Anatomical terminology | |
Theuvula (pl.:uvulas oruvulae), also known as thepalatine uvula orstaphyle, is a conic projection from the back edge of the middle of thesoft palate, composed ofconnective tissue containing a number ofracemose glands, and some muscular fibers.[1][2] It also contains manyserous glands, which produce thin saliva.[3] It is only found inhumans.[4]
The muscular part of the uvula (Latin: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 posteriorpharyngeal wall to help close thenasopharynx during swallowing.[5]
Its muscles are controlled by thepharyngeal branch of thevagus nerve.
A bifid orbifurcated uvula is a split or cleft uvula. Newborns withcleft 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. If the soft palate cannot touch the back of the throat while swallowing, food and drink can enter the nasal cavity.[6] 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,[7] although some populations may have a high incidence, such asNative Americans who have a 10% rate.[8]
Bifid uvula is a common symptom of the rare genetic syndromeLoeys–Dietz syndrome,[9] which is associated with an increased risk of aortic aneurysm.[10]
During swallowing, the soft palate and the uvula move together to close off thenasopharynx, and prevent food from entering thenasal cavity.
It has also been proposed that the abundant amount of thin saliva produced by the uvula serves to keep the throat well lubricated.[3]
It has a function in speech as well. In many languages, a range of consonant sounds, known asuvular consonants, are articulated by creating a constriction of airflow between the uvula and the back of the tongue. Thevoiced uvular trill, written[ʀ] in theInternational Phonetic Alphabet, is one example; it is used inFrench,Arabic andHebrew, among other languages. It has been suggested that the uvula is an accessory speech organ.[4]
Stimulation of the uvula also causes thegag reflex to initiate. This is often a problem for people withuvula piercings, and a common method of inducing vomiting.[citation needed]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.
At times, themucous membrane around the uvula mayswell, 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, includingdehydration (e.g. from arid weather); excessivesmoking or other inhaled irritants;snoring;allergic reaction; or aviral orbacterial infection. Anaphthous ulcer which has formed on the uvula can also cause swelling and discomfort.[11]
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 anepinephrine 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.
The uvula can also contribute tosnoring or heavy breathing during sleep; having an elongated uvula can cause vibrations that lead to snoring. In some cases this can lead tosleep apnea, which may be treated by removal of the uvula or part of it if necessary, an operation known asuvulopalatopharyngoplasty (commonly referred to as UPPP, or UP3). However, this operation can also cause sleep apnea ifscar 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.[12] 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]
In a small number of people, the uvula does not close properly against the back of the throat, causing a condition known asvelopharyngeal 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[b] like[m].
During swallowing, the soft palate and the uvula move superiorly to close off thenasopharynx, preventing food from entering thenasal cavity. When this process fails, the result is callednasal regurgitation. It is common in people withVPI, themyositides, andneuromuscular 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.
In some parts of Africa, includingSomalia,Ethiopia andEritrea, the uvula or a section of it is ritually removed by a traditional healer.[13] In this case, the uvula may be noticeably shortened. It is not thought to contribute tovelopharyngeal inadequacy, except in cases where the tonsils have also been removed.[14]
In Latin,ūvula means "little grape", the diminutive form ofūva "grape" (of unknown origin). A swollen uvula was calledūva.[15]
