If you were once examining your mouth while opening it wide, observed a small tongue-like structure bulging at the ‘end’ of your mouth, and got scared, you are not alone. This tongue-like structure is present in every human and is often considered a ‘second tongue’ – but since our tongue is well-equipped and functional, do we need a second tongue?
The answer to the question posed is no. Also, the organ seen at the visual end of the mouth is not a second tongue – instead, it is the UVULA. The word ‘uvula’ has been derived from Latin and is a word used to describe a bunch of grapes. It has a conic shape and is pink in color – two features that owe to it being called a ‘second tongue’.
The uvula is a protrusion from the SOFT PALATE of the mouth, while the TONSILS are flanked on either side of the uvula. Anatomically, the soft palate is the tissue that makes up the roof of the mouth (the other type of palate is the HARD PALATE).
What is the uvula?
The uvula is majorly made up of CONNECTIVE TISSUES and muscles and contains several glands called RACEMOSE and SEROUS GLANDS. The serous glands present in the uvula contribute to the process of chewing of the food in the mouth by producing saliva of a thinner consistency. The muscles present in the uvula, called the MUSCULUS UVULAE, oversee the morphology (i.e., appearance) of the uvula. Most muscles are involved in contraction and relaxation, while musculus uvulae engage in shortening and broadening of the uvula.
The biological necessity of the uvula is a matter of debate in the medical community. Some scientists are unable to weigh its pros and cons. Uvula, like other organs, is susceptible to infection, particularly manifesting as inflammation. Inflammation and/or infection of the uvula is usually tended to by the removal of most of the flesh of the uvula. People with shortened uvula do survive, but the absence of the thin salivary secretion causes acute dryness of the throat.
What is the role of the uvula?
The uvula has several hypothesized as well as proven functions in the human body. However, in this discussion, the clinical significance of the uvula will also be included.
- Mashing of food
Saliva and its primary constituent salivary amylase mash the food ingested in the mouth. The uvula, due to possessing salivary glands that produce watery saliva for the further mashing and breakdown of food. People who have undergone procedures to remove their uvulas have noted dryness at the edge of the throat due to this saliva not being secreted. However, such people do not undergo any change in the way the food is mashed in their mouths.
- Flow of food
The uvula is said to restrict the food to enter the NASAL CAVITIES and directs it to the OESOPHAGUS. A hypothesis suggests that the uvula works in conjunction with the epiglottis to stop the food from flowing into the trachea by a mechanism – when the food flows past the uvula, the epiglottis is triggered to cover the windpipe. Still, this hypothesis has not been fully proven. It is also possible that the brushing of the food against the roof of the mouth triggers the action of the oesophagus.
It is said that the uvula contributes to the moderation of voice and helps with a range of sounds. Particularly, words with an ‘r’ sound (produced during purring) are clearer because of the uvula. The diction of languages that make use of these sounds – Arabic, Hebrew, and French – is better with the use of the uvula.
The uvula also tends to cause a variety of problems, such as –
The vibrations of the uvula, coupled with its elongation, can contribute to a chronic snoring problem.
- Sleep apnea
SLEEP APNEA is a sleeping condition wherein the person difficultly breathing or a low respiratory rate during sleep. Removal of the uvula, performed in a surgical procedure called UVULOPALATOPHARYNGOPLASTY, has been observed to reduce the effects of sleep apnea as snoring.
The uvula is susceptible to inflammation due to allergy or infection. The resultant enlargement of the uvula can cause it to touch the tongue, thereby triggering a GAG REFLEX. It can cause breathing, talking, and eating impediments. Further, it can also cause friction against the tongue and cause scarring.
The uvula is often confused with the EPIGLOTTIS, which is the flap-like structure covering the windpipe while swallowing food. While the functions of the epiglottis and uvula are linked, the two organs are distinct and perform varied functions.