The palatine uvula, usually referred to as simply the uvula, is a conic projection from the back edge of the middle of the
soft palate
The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is the hard palate. ...
, composed of
connective tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...
containing a number of
racemose glands, and some muscular fibers. It also contains many
serous gland
Serous glands secrete serous fluid. They contain serous acini, a grouping of serous cells that secrete serous fluid, isotonic with blood plasma, that contains enzymes such as alpha-amylase.
Serous glands are most common in the parotid gland and ...
s, which produce thin saliva.
It is only found in
human beings
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, an ...
.
Structure
Muscle
The muscular part of the uvula () 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
pharyngeal wall to help close the
nasopharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...
during swallowing.
Its muscles are controlled by the
pharyngeal branch of the
vagus nerve
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right ...
.
Variation
A bifid or
bifurcated
Bifurcation or bifurcated may refer to:
Science and technology
* Bifurcation theory, the study of sudden changes in dynamical systems
** Bifurcation, of an incompressible flow, modeled by squeeze mapping the fluid flow
* River bifurcation, the for ...
uvula is a split or cleft uvula. Newborns with
cleft palate
A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The te ...
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. 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, although some populations may have a high incidence, such as
Native Americans who have a 10% rate.
Bifid uvula is a common symptom of the rare genetic syndrome
Loeys–Dietz syndrome
Loeys–Dietz syndrome (LDS) is an autosomal dominant genetic connective tissue disorder. It has features similar to Marfan syndrome and Ehlers–Danlos syndrome. The disorder is marked by aneurysms in the aorta, often in children, and the aorta ...
, which is associated with an increased risk of aortic aneurysm.
Function
During swallowing, the soft palate and the uvula move together to close off the
nasopharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...
, and prevent food from entering the
nasal cavity
The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nasal c ...
.
It has also been proposed that the abundant amount of thin saliva produced by the uvula serves to keep the throat well lubricated.
[
It has a function in speech as well. In many languages, a range of consonant sounds, known as ]uvular consonants
Uvulars are consonants articulated with the back of the tongue against or near the uvula, that is, further back in the mouth than velar consonants. Uvulars may be stops, fricatives, nasals, trills, or approximants, though the IPA does not prov ...
, are articulated by creating a constriction of airflow between the uvula and the back of the tongue. The voiced uvular trill
The voiced uvular trill is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , a small capital letter ''R''. This consonant is one of several collectively ...
, written in the International Phonetic Alphabet
The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic transcription, phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standa ...
, is one example; it is used in French, Arabic
Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...
and Hebrew
Hebrew (; ; ) is a Northwest Semitic language of the Afroasiatic language family. Historically, it is one of the spoken languages of the Israelites and their longest-surviving descendants, the Jews and Samaritans. It was largely preserved ...
, among other languages. Due to the large amount of saliva produced from glands in the uvula that are absent in other mammals, it has been suggested that the uvula is an accessory speech organ.
Stimulation of the uvula also causes the gag reflex The pharyngeal reflex or gag reflex is a reflex muscular contraction of the back of the throat, evoked by touching the roof of the mouth, the back of the tongue, the area around the tonsils, the uvula, and the back of the throat. It, along with ot ...
to initiate. This is often a problem for people with uvula piercing
A uvula piercing is a body piercing through the uvula, the projection of the soft palate between the tonsils. This is a rare piercing. Captive bead rings or other small rings are the most commonly seen jewellery in uvula piercings.
Health issues
...
s, and a common method of inducing vomiting.
Clinical significance
Inflammation
At times, the mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
around the uvula may 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
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
(e.g. from arid weather); excessive smoking
Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have bee ...
or other inhaled irritants; snoring
Snoring is the vibration of respiratory structures and the resulting sound due to obstructed air movement during breathing while sleeping. The sound may be soft or loud and unpleasant. Snoring during sleep may be a sign, or first alarm, of ob ...
; allergic reaction
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
; or a viral or bacterial infection
Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of ...
. An aphthous ulcer
Aphthous stomatitis, or recurrent aphthous stomatitis (RAS), is a common condition characterized by the repeated formation of benign and non-contagious mouth ulcers (aphthae) in otherwise healthy individuals. The informal term ''canker sore'' i ...
which has formed on the uvula can also cause swelling and discomfort.
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
An epinephrine autoinjector (or adrenaline autoinjector, also known by the trademark EpiPen) is a medical device for injecting a measured dose or doses of epinephrine (adrenaline) by means of autoinjector technology. It is most often used for t ...
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
Snoring is the vibration of respiratory structures and the resulting sound due to obstructed air movement during breathing while sleeping. The sound may be soft or loud and unpleasant. Snoring during sleep may be a sign, or first alarm, of ob ...
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
Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many times ...
, which may be treated by removal of the uvula or part of it if necessary, an operation known as uvulopalatopharyngoplasty
Uvulopalatopharyngoplasty (also known by the abbreviations UPPP and UP3) is a surgical procedure or sleep surgery used to remove tissue and/or remodel tissue in the throat. This could be because of sleep issues. Tissues which may typically be remov ...
(commonly referred to as UPPP, or UP3). However, this operation can also cause sleep apnea if scar
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a na ...
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. 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.
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
Velopharyngeal insufficiency is a disorder of structure that causes a failure of the velum (soft palate) to close against the posterior pharyngeal wall (back wall of the throat) during speech in order to close off the nose (nasal cavity) during o ...
. 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'.
Nasal regurgitation
During swallowing, the soft palate and the uvula move superiorly to close off the nasopharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struct ...
, preventing food from entering the nasal cavity
The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nasal c ...
. When this process fails, the result is called ''nasal regurgitation''. It is common in people with VPI, the myositides, and neuromuscular disease
A neuromuscular disease is any disease affecting the peripheral nervous system (PNS), the neuromuscular junction, or skeletal muscle, all of which are components of the motor unit. Damage to any of these structures can cause muscle atrophy and w ...
. 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
In some parts of Africa, including Somalia
Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
, Ethiopia
Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
and Eritrea
Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...
, the uvula or a section of it is ritually removed by a traditional healer. In this case, the uvula may be noticeably shortened. It is not thought to contribute to velopharyngeal inadequacy
Velopharyngeal inadequacy is a malfunction of a velopharyngeal mechanism which is responsible for directing the transmission of sound energy and air pressure in both the oral cavity and the nasal cavity. When this mechanism is impaired in some way, ...
, except in cases where the tonsils have also been removed.
History
Etymology
In Latin, ''ūvula'' means "little grape", the diminutive form of ''ūva'' "grape" (of unknown origin). A swollen uvula was called ''ūva''.
See also
* Uvula (disambiguation)
*Tonsil
The tonsils are a set of lymphoid organs facing into the aerodigestive tract, which is known as Waldeyer's tonsillar ring and consists of the adenoid tonsil, two tubal tonsils, two palatine tonsils, and the lingual tonsils. These organs play ...
*Epiglottis
The epiglottis is a leaf-shaped flap in the throat that prevents food and water from entering the trachea and the lungs. It stays open during breathing, allowing air into the larynx. During swallowing, it closes to prevent aspiration of food int ...
References
External links
* - Uvulitis
{{DEFAULTSORT:Palatine Uvula
Palate
Human throat
Speech organs