- Perineurium
Infobox Anatomy
Name = PAGENAME
Latin =
GraySubject = 183
GrayPage = 728
Caption = Transverse section of humantibial nerve . (Perineurium labeled at upper right.)
Caption2 = Nerve structure
System =
MeshName = Perineurium
MeshNumber = A08.800.800
DorlandsPre = p_13
DorlandsSuf = 12627709
In thespinal cord , nerve fibers are each wrapped in a protective sheath known as theendoneurium . These are bundled together into groups known as fascicles, each surrounded by a protective sheath known as the perineurium. Several fascicles may be in turn bundled together with a blood supply and fatty tissue within yet another sheath, theepineurium . This grouping structure is analogous to the muscular organization system ofepimysium ,perimysium andendomysium .The perineurium is composed of
connective tissue , which has a distinctly lamellar arrangement consisting of roughly 7-8 concentric layers. The perineurium is cellular, and is composed of perineurial cells, which areepithelioid myofibroblasts . Perineurial cells are sometimes referred to asmyoepithelioid due to theirepithelioid andmyofibroblastoid properties includingtight junctions ,gap junctions ,external laminae and contractility.The perineurium is a smooth, transparent tubular membrane which may be easily separated from the fibers it encloses. In contrast, the
epineurium is a tough and mechanically resistant tissue which is not easily penetrated by a needle.External links
*
* - "Peripheral nerve"
* - "PNS, nerve (LM, Low)"
*
* [http://www.med.howard.edu/anatomy/gas/wk2/images/image2.gifDiagram at Howard]
* [http://neuromedia.neurobio.ucla.edu/campbell/nervous/wp_images/182%20endoneurium%20LP.jpgHistology at ucla.edu]
Wikimedia Foundation. 2010.