| Elastic cartilage | |
|---|---|
.jpg) A cross section of mammalian elastic cartilage | |
 Lateral side of theauricle | |
| Details | |
| Part of | Outer ear,Eustachian tube andepiglottis |
| Identifiers | |
| Latin | cartilago elastica |
| MeSH | D051472 |
| TH | H2.00.03.5.00018 |
| FMA | 64785 |
| Anatomical terminology | |
Elastic cartilage,fibroelastic cartilage oryellow fibrocartilage[1] is a type ofcartilage present in thepinnae (auricles) of the ear giving it shape,[2] provides shape for the lateral region of theexternal auditory meatus,[3] medial part of theauditory canal[3]Eustachian tube,corniculate andcuneiform laryneal cartilages,[3] and theepiglottis. It contains elastic fiber networks and collagen type II fibers.[4] The principal protein iselastin.
Elastic cartilage ishistologically similar tohyaline 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 usinghaematoxylin and eosin (H&E) stain it appears the same as hyaline cartilage.[3] Verhoeff van Geison stains are used (giving the elastic fibers a black color), but aldehyde fuchsin stains,Weigert's elastic stains, andorcein stains also work.[3] 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.[2] The chondrocytes only make up 2% of the tissue's volume.[2] Chondrocytes and the extracellular matrix are contained in an outerlayer named theperichondrium[2] (which is a layer of dense irregular connective tissue that surrounds cartilage which is independent of the joint).[3] It is found in the epiglottis (part of the larynx), and thepinnae (the external ear flaps of many mammals). Elastin fibers stain dark purple/black withVerhoeff's stain.
The extracellular matrix containsElastin,fibrillin,glycoproteins,collagen typesII, IX, X, and XI, and theproteoglycanaggrecan.[2] the components within the extracellular matrix are produced by thechondroblasts located within the edges of the perichondrium.[2]
Elastic fibers within the extracellular matrix are made up of elastin proteins whichco-polymerize with fibrillin forming fiber-like elastic chains.[2] When the elastic fibers are relaxed the elastic chains appear disorganized, whentensile pressure is give the elastic chains appear organized and return to a disorganized state when the pressure is released.[2]
Collagen fibers form networks to provide strength and structural framework for the molecules within the extracellular matrix.[2]
List of distinct cell types in the adult human body
This article incorporates text in thepublic domain frompage 279 of the 20th edition ofGray's Anatomy(1918)
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