|The human tongue|
|Medical illustration of a human mouth by Duncan Kenneth Winter.|
|Gray's||subject #242 1125|
|Artery||lingual, tonsillar branch, scending pharyngeal|
|Nerve||Anterior 2/3: lingual nerve & chorda tympani Posterior 1/3: Glossopharyngeal nerve (IX)|
|Precursor||pharyngeal arches, lateral lingual swelling, tuberculum impar1|
|This article needs additional citations for verification. (June 2008)|
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste (gustation), as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly supplied with nerves and blood vessels. In humans a secondary function of the tongue is phonetic articulation. The tongue also serves as a natural means of cleaning one's teeth.2 The ability to perceive different tastes is not localised in different parts of the tongue, as is widely believed.3 This error arose because of misinterpretation of some 19th-century research (see tongue map).
- 1 Etymology
- 2 Description
- 3 Length
- 4 Physiology
- 5 Pathology
- 6 Sublingual medication
- 7 Non-human tongues
- 8 Cultural aspects
- 9 Additional Images
- 10 See also
- 11 References
- 12 External links
The word tongue derives from the Old English tunge, which comes from Proto-Germanic *tungōn.4 It has cognates in other Germanic languages — for example tonge in West Frisian, tong in Dutch/Afrikaans, Zunge in German, tunge in Danish/Norwegian and tunga in Icelandic/Faroese/Swedish. The ue ending of the word seems to be a fourteenth-century attempt to show "proper pronunciation", but it is "neither etymological nor phonetic".4 Some used the spelling tunge and tonge as late as the sixteenth century.
A common temporary failure in word retrieval from memory is referred to as the tip-of-the-tongue phenomenon. The expression tongue in cheek refers to a statement that is not to be taken entirely seriously – something said or done with subtle ironic or sarcastic humour. A tongue twister is a phrase made specifically to be very difficult to pronounce. Aside from being a medical condition, "tongue-tied" means being unable to say what you want to due to confusion or restriction. The phrase "cat got your tongue" refers to when a person is speechless. To "bite one's tongue" is a phrase which describes holding back an opinion to avoid causing offence. A "slip of the tongue" refers to an unintentional utterance, such as a Freudian slip. Speaking in tongues is a common phrase used to describe glossolalia, which is to make smooth, language-resembling sounds that is no true spoken language itself. A deceptive person is said to have a forked tongue, and a smooth-talking person said to have a Silver Tongue.
The eight muscles of the human tongue are classified as either intrinsic or extrinsic. The four intrinsic muscles act to change the shape of the tongue, and are not attached to any bone. The four extrinsic muscles act to change the position of the tongue, and are anchored to bone.
The extrinsic muscles originate from bone and extend to the tongue. Their main functions are altering the tongue's position allowing for protrusion, retraction, and side-to-side movement.
The main function of the intrinsic muscles is to provide shape. They are not involved with changing the position of the tongue and are not attached to bone.
The tongue receives its blood supply primarily from the lingual artery, a branch of the external carotid artery and lingual veins which drain into internal jugular vein. The floor of the mouth also receives its blood supply from the lingual artery. The triangle formed by the intermediate tendon of the digastric muscle, the posterior border of the mylohyoid muscle, and the hypoglossal nerve is sometimes called Pirogov's, Pirogoff's, or Pirogov-Belclard's triangle.67 The lingual artery is a good place to stop severe hemorrage from the tongue.
Anterior 2/3rds of tongue
- General somatic afferent: lingual nerve branch of V3 of the trigeminal nerve CN V. Origin Surperficial ectoderm.
- Taste: chorda tympani branch of facial nerve CN VII (carried to the tongue by the lingual nerve).
Posterior 1/3rd of tongue
- All intrinsic and extrinsic muscles of the tongue are supplied by the hypoglossal nerve (CN XII), except for one of the extrinsic muscles, palatoglossus, which is innervated by the Vagus nerve CN X of the pharyngeal plexus.
Chemicals that stimulate taste receptor cells are known as tastants. Once a tastant is dissolved in saliva, it can make contact with the plasma membrane of the gustatory hairs, which are the sites of taste transduction.9
The tongue is equipped with many taste buds on its dorsal surface, and each taste bud is equipped with taste receptor cells that can sense particular classes of tastes. There are taste cells for: sweet, bitter, salty or sour, and umami.10 Umami receptor cells are the least understood but research into the key features is making progress.11
After the gums, the tongue is the second most common soft tissue site for various pathologies in the oral cavity.medical citation needed Examples of pathological conditions of the tongue include glossitis (e.g. geographic tongue, median rhomboid glossitis), burning mouth syndrome, oral hairy leukoplakia, oral candidiasis and squamous cell carcinoma.12
The sublingual region underneath the front of the tongue is a location where the oral mucosa is very thin, and underlain by a plexus of veins. This is an ideal location for introducing certain medications to the body. The sublingual route takes advantage of the highly vascular quality of the oral cavity, and allows for the speedy application of medication into the cardiovascular system, bypassing the gastrointestinal tract. This is the only convenient and efficacious route of administration (apart from I.V. administration) of nitroglycerin to a patient suffering chest pain from angina pectoris.
Most vertebrate animals have tongues. In mammals such as dogs and cats, the tongue is often used to clean the fur and body. The tongues of these species have a very rough texture which allows them to remove oils and parasites. A dog's tongue also acts as a heat regulator. As a dog increases its exercise the tongue will increase in size due to greater blood flow. The tongue hangs out of the dog's mouth and the moisture on the tongue will work to cool the bloodflow.1314
Other animals may have organs that are analogous to tongues, such as a butterfly's proboscis or a radula on a mollusc, but these are not homologous with the tongues found in vertebrates, and often have little resemblance in function, for example, butterflies do not lick with their proboscides; they suck thorough them, and the proboscis is not a single organ, but two jaws held together to form a tube.17
The tongues of some animals are consumed and sometimes considered delicacies. Hot tongue sandwiches are frequently found on menus in Kosher delicatessens in America. Taco de lengua (lengua being Spanish for tongue) is a taco filled with beef tongue, and is especially popular in Mexican cuisine. As part of Colombian gastronomy, Tongue in Sauce (Lengua en Salsa), is a dish prepared by frying the tongue, adding tomato sauce, onions and salt. Tongue can also be prepared as birria. Pig and beef tongue are consumed in Chinese cuisine. Duck tongues are sometimes employed in Szechuan dishes, while lamb's tongue is occasionally employed in Continental and contemporary American cooking. Fried cod "tongue" is a relatively common part of fish meals in Norway and Newfoundland. In Argentina and Uruguay cow tongue is cooked and served in vinegar (lengua a la vinagreta). In the Czech Republic and Poland, a pork tongue is considered a delicacy,and there are many ways of preparing it. In Eastern Slavic countries, pork and beef tongues are commonly consumed, boiled and garnished with horseradish or jelled; beef tongues fetch a significantly higher price and are considered more of a delicacy. In Alaska, cow tongues are among the more common.
Tongues of seals and whales have been eaten, sometimes in large quantities, by sealers and whalers, and in various times and places have been sold for food on shore.18
Sticking one's tongue out at someone is considered a childish gesture of rudeness and/or defiance in many countries; the act may also have sexual connotations, depending on the way in which it is done. However, in Tibet it is considered a greeting.19 In 2009, a farmer from Fabriano, Italy was convicted and fined by the country's highest court for sticking his tongue out at a neighbor with whom he had been arguing. Proof of the affront had been captured with a cell phone camera.20 Blowing a raspberry can also be meant as a gesture of derision.
- Body art
Being a cultural custom for long time, tongue piercing and splitting has become quite common in western countries in recent decades, with up to one-fifth of young adults having at least one piece of body art in the tongue.21
- hednk-024 — Embryo Images at University of North Carolina
- Maton, Anthea; Hopkins, Jean; McLaughlin, Charles William; Johnson, Susan; Warner, Maryanna Quon; LaHart, David; Wright, Jill D. (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall. ISBN 0-13-981176-1.
- The Taste Map: All Wrong Scientific American, 2001-03-18.
- Online Etymology Dictionary
- Afrikaans tong; Danish tunge; Albanian gjuha; Armenian lezu (լեզու); Greek glóssa (γλώσσα); Irish teanga; Manx çhengey; Latin and Italian lingua; Catalan llengua; French langue; Portuguese língua; Spanish lengua; Romanian limba; Bulgarian ezik (език); Polish język; Russian yazyk (язык); Czech and Slovak jazyk; Slovene, Bosnian, Croatian, and Serbian jezik; Kurdish ziman (زمان); Persian and Urdu zabān (زبان); Arabic lisān (لسان); Aramaic liššānā (ܠܫܢܐ/לשנא); Hebrew lāšon (לָשׁוֹן); Maltese ilsien; Estonian keel; Finnish kieli; Hungarian nyelv; Azerbaijani and Turkish dil; Kazakh and Khakas til (тіл)
- Pirogov's triangle
- Jamrozik, T.; Wender, W. (January 1952). "Topographic anatomy of lingual arterial anastomoses; Pirogov-Belclard's triangle". Folia Morphologica 3 (1): 51–62. PMID 13010300.
- Kerrod, Robin (1997). MacMillan's Encyclopedia of Science 6. Macmillan Publishing Company, Inc. ISBN 0-02-864558-8.
- Tortora. Principles of Anatomy and Physiology 12th edition, chapter 17, p.602.
- Silverhorn. Human Physiology: An integrated approach 5th edition, chapter 10, p.352.
- Schacter, Daniel L., Daniel Todd. Gilbert, and Daniel M. Wegner. "Sensation and Perception." Psychology. 2nd ed. New York: Worth, 2009. 166. Print.
- Lam, L.; Logan, R. M.; Luke, C. (March 2006). "Epidemiological analysis of tongue cancer in South Australia for the 24-year period, 1977-2001". Aust Dent J 51 (1): 16–22. doi:10.1111/j.1834-7819.2006.tb00395.x. PMID 16669472.
- A dog's tongue
- Krönert, H.; Pleschka, K. (January 1976). "Lingual blood flow and its hypothalamic control in the dog during panting". Pflügers Archiv European Journal of Physiology 367 (1): 25–31. doi:10.1007/BF00583652. ISSN 0031-6768. Retrieved June 24, 2011.
- Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 298–299. ISBN 0-03-910284-X.
- Kingsley, John Sterling (1912). Comparative anatomy of vertebrates. P. Blackiston's Son & Co. pp. 217–220. ISBN 1-112-23645-7.
- Richards, O. W.; Davies, R. G. (1977). Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development Volume 2: Classification and Biology. Berlin: Springer. ISBN 0-412-61390-5.
- CHARLES BOARDMAN HAWES. Whaling. Doubleday, 1924
- Bhuchung K Tsering (27 December 2007). "Tibetan culture in the 21st century". Retrieved 13 February 2012.
- Sticking out your tongue ruled illegal
- Liran, Levin; Yehuda, Zadik; Tal, Becker (December 2005). "Oral and dental complications of intra-oral piercing". Dent Traumatol 21 (6): 341–3. doi:10.1111/j.1600-9657.2005.00395.x. PMID 16262620. Retrieved 2008-07-16.
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