The uvula (pl.: uvulas or uvulae), also known as the palatine uvula, is a conic projection from the back edge of the middle of the soft palate, composed of connective tissue containing a number of racemose glands, and some muscular fibers.[1][2] It also contains many serous glands, which produce thin saliva.[3] It is only found in humans.[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 posterior pharyngeal wall to help close the nasopharynx during swallowing.[5]
A bifid or bifurcated uvula is a split or cleft uvula. Newborns with 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. 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 as Native Americans who have a 10% rate.[8]
Bifid uvula is a common symptom of the rare genetic syndrome Loeys–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 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.[3]