View source for Elastic cartilage

{{Short description|Type of tissue}}
{{Infobox anatomy
| Name        = Elastic cartilage
| Latin       = cartilago elastica
| Image = Connective Tissue Elastic Cartilage (41855667361).jpg
| Caption = A cross section of mammalian elastic cartilage
| Image2 = Gray904.png
| Caption2 = Lateral side of the [[auricle (anatomy)|auricle]]
| System      =
| PartOf = [[Outer ear]], [[Eustachian tube]] and [[epiglottis]]
}}
'''Elastic cartilage''', '''fibroelastic cartilage''' or '''yellow fibrocartilage''' <ref>{{Cite web |title=Elastic cartilage histology |url=https://www.kenhub.com/en/library/anatomy/histology-of-elastic-cartilage |access-date=2022-03-08 |website=Kenhub |language=en}}</ref> is a type of [[cartilage]] present in the [[Auricle (anatomy)|pinnae]] (auricles) of the ear giving it shape,<ref name=":0">{{Cite web|last=Editors|first=B. D.|date=2019-04-26|title=Elastic Cartilage|url=https://biologydictionary.net/elastic-cartilage/|access-date=2021-03-12|website=Biology Dictionary|language=en-US}}</ref> provides shape for the lateral region of the [[External Auditory Meatus|external auditory meatus]],<ref name=":1">{{Cite web|title=Elastic cartilage histology|url=https://www.kenhub.com/en/library/anatomy/histology-of-elastic-cartilage|access-date=2021-03-12|website=Kenhub|language=en}}</ref> medial part of the [[auditory canal]]<ref name=":1" /> [[Eustachian tube]], [[Corniculate cartilages|corniculate]] and [[Cuneiform cartilages|cuneiform]] laryneal cartilages,<ref name=":1" /> and the [[epiglottis]].  It contains elastic fiber networks and collagen type II fibers.<ref name=dictionary>{{cite web|title=Elastic cartilage|url=http://www.merriam-webster.com/medlineplus/elastic%20cartilage|website=Medline Plus/Merriam-Webster Dictionary|access-date=1 March 2015}}</ref> The principal protein is [[elastin]].

==Structure==
Elastic cartilage is [[histology|histologically]] similar to [[hyaline cartilage]] but contains many yellow elastic fibers lying in a solid matrix. These fibers form bundles that appear dark under a microscope. The elastic fibers require special staining since when it is stained using [[Haematoxylin and eosin stain|haematoxylin and eosin (H&E)]] stain it appears the same as hyaline cartilage.<ref name=":1" /> Verhoeff van Geison stains are used (giving the elastic fibers a black color), but aldehyde fuchsin stains, [[Weigert's elastic stain|Weigert's elastic stains]], and [[Orcein stain|orcein stains]] also work.<ref name=":1" /> These fibers give elastic cartilage great flexibility so that it is able to withstand repeated bending. Similarly to hyaline one or multiple chondrocytes lie between the spaces (or lacunea) in the fibres.<ref name=":0" /> The chondrocytes only make up 2% of the tissue's volume.<ref name=":0" /> Chondrocytes and the extracellular matrix are contained in an outerlayer named the [[perichondrium]]<ref name=":0" /> (which is a layer of dense irregular connective tissue that surrounds cartilage which is independent of the joint).<ref name=":1" /> It is found in the epiglottis (part of the larynx), and the [[pinna (anatomy)|pinnae]] (the external ear flaps of many mammals). Elastin fibers stain dark purple/black with [[Verhoeff's stain]].

The extracellular matrix contains [[elastin]], [[fibrillin]], [[Glycoprotein|glycoproteins]], [[collagen]] types [[Type II collagen|II]], IX, X, and XI, and the [[proteoglycan]] [[aggrecan]].<ref name=":0" /> the components within the extracellular matrix are produced by the [[Chondroblast|chondroblasts]] located within the edges of the perichondrium.<ref name=":0" /> 

Elastic fibers within the extracellular matrix are made up of elastin proteins which [[Copolymerization|co-polymerize]] with fibrillin forming fiber-like elastic chains.<ref name=":0" /> When the elastic fibers are relaxed the elastic chains appear disorganized, when [[Tension (physics)|tensile]] pressure is give the elastic chains appear organized and return to a disorganized state when the pressure is released.<ref name=":0" />

Collagen fibers form networks to provide strength and structural framework for the molecules within the extracellular matrix.<ref name=":0" />

==Function==
* Provide support<ref name=":0" />
* Maintain shape in response to tension, compression, and bending<ref name=":0" />

== See also ==
[[List of distinct cell types in the adult human body]]

==References==
{{Gray's}}
<references />

==External links==
* {{OklahomaHistology|12_02}} - "epiglottis"
* {{BUHistology|02901loa}}
* [http://meded.ucsd.edu/hist-img-bank/chapter_2/Slide_14_elastic/index.htm Histology at ucsd.edu] {{Webarchive|url=https://web.archive.org/web/20120205203051/http://meded.ucsd.edu/hist-img-bank/chapter_2/Slide_14_elastic/index.htm |date=2012-02-05 }}
* {{AnatomyAtlasesMicroscopic|03|42}}

{{Bone and cartilage}}
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[[Category:Connective tissue]]


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