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{{Short description|Rounded outgrowth found on external or internal organs of plants or animals}}
{{forFor|the lip feature|Cupid's bow}}
[[Image:Mammillaria marksiana.jpg|right|250px|thumb|This view of the cactus ''[[Mammillaria marksiana]]'' shows its pattern of prominent tubercles, with the spines emanating from each tubercle's tip.]]
 
In [[anatomy]], a '''tubercle''' (literally 'small tuber', Latin for 'lump') is any round [[Nodule (medicine)|nodule]], small [[wikt:eminence|eminence]], or [[wart]]y outgrowth found on external or internal organs[[Organ (anatomy)|organ]]s of a plant or an animal.
 
==In plants==
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In the case of certain [[orchid]]s and [[cactus|cacti]], it denotes a round nodule, small [[wikt:eminence|eminence]], or [[wart]]y outgrowth found on the [[Labellum (botany)|lip]]. They are also known as podaria (singular ''podarium''). When referring to some members of the [[Fabaceae|pea family]], it is used to refer to the wart-like excrescences that are found on the roots.
 
==In fungi==
In [[mycology]], a tubercle is used to refer to a mass of [[hypha]]e from which a [[mushroom]] is made.
 
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[[File:Phyllidia.jpg|thumb|right|Nudibranch ''[[Phyllidia varicosa]]'', clearly showing the yellow tubercles on the dorsum]]
 
When it is used in relation to certain dorid [[nudibranch]]s such as ''[[Peltodoris nobilis]]'', it means the nodules on the dorsum of the animal. TheseThe tubercles in nudibranchs can present themselves in different ways: each tubercle in a single, rounded, conical or angular form, each tubercle in a compound form of two 2 or more levels, tubercles in amalgamated clusters or as tubercles forming, or joined by a ridge.
 
Tubercles found on the leading edge of [[humpback whale]]'s' flippers were demonstrated to improve fluid flow over the flipper's surface, exhibiting the [[tubercle effect]] of fluid dynamics.<ref>[http://www{{cite journal | doi=10.dtic.mil1063/dtic/tr/fulltext/u2/a5115171.pdf1688341 | title=Leading-edge tubercles delay stall on humpback whale ( ''Megaptera novaeangliae'' ) flippers], DS| date=2004 | last1=Miklosovic, MM| first1=D. S. | last2=Murray, LE| first2=M. M. | last3=Howle, FE| first3=L. E. | last4=Fish, | first4=F. E. | journal=Physics of Fluids (1994-present)| volume=16 (| issue=5), L39-L42,| 2004pages=L39–L42 | bibcode=2004PhFl...16L..39M }}</ref>
 
[[File:Edmontosaurusskin.jpg|thumb|right|Skin impression from the abdomen of the [[hadrosaurid|duck-billed]] [[dinosaur]] ''[[Edmontosaurus|Edmontosaurus annectens]]'', showing tubercular scales]]
 
In [[dinosaur]]s, a tubercle is a general term for the scales seen in skin impressions. In [[hadrosaurid|duck-billed dinosaurs]], for example, three main types of tubercles are defined: small tubercles with no definite arrangement (ground tubercles); larger, [[polygon]]al tubercles (pavement tubercles) up to {{cvt|1&nbsp;|cm (0.4&nbsp;|in)}} in diameter, which are grouped into clusters separated by ground tubercles; and [[limpet]]-shaped conical scutes.<ref name=LW42>{{cite book |last=Lull |first=Richard Swann |authorlinkauthor-link=Richard Swann Lull |author2=Wright, Nelda E. |title=Hadrosaurian Dinosaurs of North America |year=1942 |publisher=[[Geological Society of America]] |series=Geological Society of America Special Paper '''|volume=40''' |pages=111–112 }}</ref>
 
In fish, [[nuptial tubercles]] are formed on males for breeding. [[Nuptial pads]] on frogs also comprise [[keratin]]ised tubercles.
 
==In humans==
Within the human body, there are numerous sites where tubercles develop. On bones, they are usually eminences used for [[muscle]] connections. Larger tubercles are also known as ''tuberosities''. Within the lungs and on the genitals, tubercles are pathological.
 
===Mouth===
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===Bones===
{{Main|Tubercle (human skeleton)}}
[[File:Osifikace apofýzy 001 num.svg|thumb|Apophysis ossification: 1&nbsp;–&nbsp;epiphyseal ossification centre; 2&nbsp;–&nbsp;diaphysis; 3&nbsp;–&nbsp;apophyseal ossification centre]]
In the [[human skeleton]], a ''tubercle'' or ''tuberosity'' is a protrusion that serves as an attachment for [[skeletal muscle]]s. The muscles attach by [[tendon]]s, where the [[enthesis]] is the connective tissue between the tendon and [[bone]].<ref>{{cite web|url=http://www.medcyclopaedia.com/library/topics/volume_iii_1/e/enthesis.aspx|archive-url=https://archive.today/20120205102809/http://www.medcyclopaedia.com/library/topics/volume_iii_1/e/enthesis.aspx|url-status=dead|archive-date=2012-02-05|title=enthesis|publisher=[[General Electric|GE]]|work=Medcyclopaedia}}</ref> For example, the [[tibial tuberosity]] creates an attachment point for the [[knee|ligamentum patellae]], or patellar ligament.
 
The [[humerus]] of the upper arm has two tubercles, the [[greater tubercle]] and the [[lesser tubercle]]. These are situated at the proximal end of the bone, that is the end that connects with the [[scapula]]. The greater/lesser tubercule are located from the top of the [[acromion]] laterally and inferiorly. The radius has two, the [[radial tuberosity]] and [[Lister's tubercle]].{{citation needed|date=February 2016}}
 
The most prominent tubercle of the [[tibia]], a leg bone which is more commonly known as the shinbone or shankbone, is the [[tibial tuberosity]]. The tibial tuberosity is located on the tibia's [[anterior]] surface, [[Anatomical terms of location#Proximal and distal|distal]] to the [[medial condyle of tibia|medial condyle]]. It creates a bony prominence just below the [[patella]], and can be easily located with the fingers. It creates an attachment point for the [[knee|ligamentum patellae]], or patellar ligament. Other tubercles of the tibia include the [[medial intercondylar tubercle]], the [[lateral intercondylar tubercle]], and [[Gerdy's tubercle]].{{citation needed|date=February 2016}}
 
On a [[rib cage|rib]], tubercle is an eminence on the back surface, at the junction between the neck and the body of the rib. It consists of an articular and a non-articular area. The lower and more medial articular area is a small oval surface for articulation with the transverse process of the lower of the two vertebrae which gives attachment to the head. The higher, non-articular area is a rough elevation which gives attachment to the ligament of the tubercle. The tubercle is much more prominent in the upper ribs than in the lower ribs.{{citation needed|date=February 2016}}
 
===Lungs===
{{mainMain|Tuberculosis}}
Tubercles are nodules that contain [[caseous necrosis]], which form in the lungs develop as a result of an infection by thewith ''[[Mycobacterium tuberculosis]]'' bacterium in the diseasepatients with [[tuberculosis]]. [[Granuloma]]s form in the infected tissue and undergo [[necrosis]] in the centre. Tubercles are also known as tuberculous nodules, or [[tuberculoma]]s. The affected parts develop lesions in the form of small nodules called tubercles, from which the disease gets its name.
 
===Ears===
Around the sixth week of gestation, six swellings of tissue, called the ''hillocks of HissHis'',{{efn|Named after [[Wilhelm His Sr.]] who first described them in 1855.<ref>Davis, Jack (1997). ''Otoplasty''. Springer, p. 24. {{ISBN|978-1-4612-7484-1}}</ref>}} arise around the area that will form the [[ear]] canal.<ref name="Anthwal">{{cite journal |last1=Anthwal |first1=Neal |last2=Thompson |first2=Hannah |title=The development of the mammalian outer and middle ear |journal=Journal of Anatomy |date=February 2016 |volume=228 |issue=2 |pages=217–232 |doi=10.1111/joa.12344|pmc=4718165 }}</ref> These eventually coalesce to form the outer ear. [[Darwin's tubercle]], is a minor malformation of the junction of the fourth and fifth hillocks of HissHis. It is found in a substantial minority of people and takes the form of a cartilaginous node or bump on the rim of their outer ear, which is thought to be the vestige of a joint that allowed the top part of the ancestral ear to swivel or flop down over the opening to the ear.<ref>{{cite news |title=Five things humans no longer need |author=Laura Spinney |url=https://www.newscientist.com/article/dn13927-five-things-humans-no-longer-need.html |newspaper=NewScientist.com news service |date=19 May 2008 <!--DASHBot-->| archiveurlarchive-url=https://web.archive.org/web/20080724005343/http://www.newscientist.com/article/dn13927-five-things-humans-no-longer-need.html | archivedatearchive-date=24 July 2008 | deadurlurl-status= nolive}}</ref>
 
===Genitals===
The [[genital tubercle]] is a small bump that eventually develops into a [[Human penis|penis]] or a [[clitoris]] on a human [[fetus]].
 
===Brain===
The [[septotubercular tract]] can be found in the human, as well as in the sheep brain. It is found nearby the [[septohypothalamic tract]]. Its function to the brain is ambiguous at this point.{{citation needed|date=November 2013}}
 
Also, the [[tuberculum sellae]] is found at the base of the skull, which holds the [[Pituitary gland|hypophysis]].
 
==See also==
* [[Areolar glands]], sebaceous glands surrounding the nipple
 
==Notes==
{{notelist}}
 
==References==
* {{Gray's}}
{{reflistReflist}}
 
== External links ==
* [http://www.cactus-art.biz/note-book/Dictionary/Dictionary_T/dictionary_tubercle.htm Tubercle at Cactus-Art.biz]
 
{{Authority control}}
 
[[Category:Human anatomy]]
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