Perineurium: Difference between revisions
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Code = [[Terminologia Anatomica|TA]] A14.2.00.015 | |
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In the [[peripheral nervous system]], nerve fibers are each wrapped in a protective sheath known as the [[endoneurium]]. These are bundled together into groups known as [[Nerve fascicle|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, the [[epineurium]]. This grouping structure is analogous to the muscular organization system of [[epimysium]], [[perimysium]] and [[endomysium]]. |
In the [[peripheral nervous system]], nerve fibers are each wrapped in a protective sheath known as the [[endoneurium]]. These are bundled together into groups known as [[Nerve fascicle|fascicles]], each surrounded by a protective sheath known as the '''perineurium'''.<ref>{{cite book|last=McCracken|first=Thomas|title=New Atlas of Human Anatomy|year=1999|publisher=Metro Books|location=China|isbn=1-5866-3097-0|pages=96-97}}</ref> Several fascicles may be in turn bundled together with a [[blood supply]] and [[fatty tissue]] within yet another sheath, the [[epineurium]]. This grouping structure is analogous to the muscular organization system of [[epimysium]], [[perimysium]] and [[endomysium]]. |
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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 are [[epithelioid]] [[myofibroblasts]]. Perineurial cells are sometimes referred to as [[myoepithelioid]] due to their [[epithelioid]] and [[myofibroblastoid]] properties including [[tight junctions]], [[gap junctions]], [[external laminae]] and contractility. |
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 are [[epithelioid]] [[myofibroblasts]]. Perineurial cells are sometimes referred to as [[myoepithelioid]] due to their [[epithelioid]] and [[myofibroblastoid]] properties including [[tight junctions]], [[gap junctions]], [[external laminae]] and contractility. |
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Revision as of 03:18, 20 April 2012
| Perineurium | |
|---|---|
 Transverse section of human tibial nerve. (Perineurium labeled at upper right.) | |
 Nerve structure | |
| Identifiers | |
| TA98 | A14.2.00.015 |
| TA2 | 6156 |
| FMA | 52585 |
| Anatomical terminology | |
In the peripheral nervous system, nerve fibers are each wrapped in a protective sheath known as the endoneurium. These are bundled together into groups known as fascicles, each surrounded by a protective sheath known as the perineurium.[1] Several fascicles may be in turn bundled together with a blood supply and fatty tissue within yet another sheath, the epineurium. This grouping structure is analogous to the muscular organization system of epimysium, perimysium and endomysium.
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 are epithelioid myofibroblasts. Perineurial cells are sometimes referred to as myoepithelioid due to their epithelioid and myofibroblastoid properties including tight 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.
See also
External links
- Template:EMedicineDictionary
- Histology image: 1_03 at the University of Oklahoma Health Sciences Center - "Peripheral nerve"
- Anatomy photo: nervous/pns/nerve1/nerve2 - Comparative Organology at University of California, Davis - "PNS, nerve (LM, Low)"
- Histology image: 21401loa – Histology Learning System at Boston University
- Diagram at Howard
- Histology at ucla.edu
 | This neuroscience article is a stub. You can help Wikipedia by expanding it. |
- ^ McCracken, Thomas (1999). New Atlas of Human Anatomy. China: Metro Books. pp. 96–97. ISBN 1-5866-3097-0.