Perineurium: Difference between revisions

Perineurium
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 [edit on Wikidata]

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Latest revision as of 19:43, 17 August 2024

The perineurium is a protective sheath that surrounds a nerve fascicle.^[1] This bundles together axons targeting the same anatomical location.^[1] The perineurium is composed from fibroblasts.^[2]

In the peripheral nervous system, the myelin sheath of each axon in a nerve is wrapped in a delicate protective sheath known as the endoneurium. Fascicles, bundles of neurons, are surrounded by 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.

Structure

The perineurium is composed of connective tissue, which has a distinctly lamellar arrangement consisting of one to several concentric layers. The perineurium 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 tight junctions provide selective barrier to chemical substances.

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.

Clinical importance

The perineurium, as the epineurium, has a clinical importance following a trauma, like a fracture. A sort of lesion called axonotmesis^[3] can happen, where the axon of the nerve is damaged while the integrity of the perineurium and epineurium is preserved. In that case, there will be a loss of neural transmission which will be causing a diminished response in the distal part of the nerve. The axon will be able to regenerate itself at a rate of 3 cm per month, generally indicating a return to a physiological state in roughly three months.

References

^ ^a ^b McCracken, Thomas (1999). New Atlas of Human Anatomy. China: Metro Books. pp. 96–97. ISBN 1-5866-3097-0.
^ Weerasuriya, ANANDA (2005-01-01), Dyck, Peter J.; Thomas, P. K. (eds.), "Chapter 29 - Blood-Nerve Interface and Endoneurial Homeostasis", Peripheral Neuropathy (Fourth Edition), Philadelphia: W.B. Saunders, pp. 651–665, doi:10.1016/b978-0-7216-9491-7.50032-6, ISBN 978-0-7216-9491-7, retrieved 2020-11-18
^ Netter, Frank. Netter's Orthopaedics.

External links

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

[:0-1] McCracken, Thomas (1999). New Atlas of Human Anatomy. China: Metro Books. pp. 96–97. ISBN 1-5866-3097-0.

[2] Weerasuriya, ANANDA (2005-01-01), Dyck, Peter J.; Thomas, P. K. (eds.), "Chapter 29 - Blood-Nerve Interface and Endoneurial Homeostasis", Peripheral Neuropathy (Fourth Edition), Philadelphia: W.B. Saunders, pp. 651–665, doi:10.1016/b978-0-7216-9491-7.50032-6, ISBN 978-0-7216-9491-7, retrieved 2020-11-18

[3] Netter, Frank. Netter's Orthopaedics.

[1]

[2]

[3]

@@ Line 1: / Line 1: @@
+{{Short description|Sheath around nerve fasciculi}}
 {{Infobox anatomy
 | Name        = Perineurium
 | Latin       =
 | Greek       =
-| GraySubject = 183
-| GrayPage    = 728
 | Image       = Gray636.png
-| Caption     = Transverse section of human [[tibial nerve]]. (Perineurium labeled at upper right.)
+| Caption     = Transverse section of human [[tibial nerve]] (perineurium labeled at upper right)
 | Width       =
 | Image2      = Illu nerve structure.jpg
 | Caption2    = Nerve structure
-| ImageMap    =
-| MapCaption  =
 | Precursor   =
 | System      =
@@ Line 18: / Line 15: @@
 | Nerve       =
 | Lymph       =
-| MeshName    = Perineurium
-| MeshNumber  = A08.800.800
-| Code        =
-| Dorlands    = p_13
-| DorlandsID  = 12627709
 }}
+The '''perineurium''' is a protective sheath that surrounds a [[nerve fascicle]].<ref name=":0">{{cite book|last=McCracken|first=Thomas|title=New Atlas of Human Anatomy|publisher=Metro Books|year=1999|isbn=1-5866-3097-0|location=China|pages=96–97}}</ref> This bundles together [[Axon|axons]] targeting the same anatomical location.<ref name=":0" /> The perineurium is composed from [[Fibroblast|fibroblasts]].<ref>{{Citation|last=Weerasuriya|first=ANANDA|title=Chapter 29 - Blood-Nerve Interface and Endoneurial Homeostasis|date=2005-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780721694917500326|work=Peripheral Neuropathy (Fourth Edition)|pages=651–665|editor-last=Dyck|editor-first=Peter J.|place=Philadelphia|publisher=W.B. Saunders|language=en|doi=10.1016/b978-0-7216-9491-7.50032-6|isbn=978-0-7216-9491-7|access-date=2020-11-18|editor2-last=Thomas|editor2-first=P. K.}}</ref>
-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]].
+In the [[peripheral nervous system]], the [[Myelin|myelin sheath]] of each axon in a nerve is wrapped in a delicate protective sheath known as the [[endoneurium]]. Fascicles, bundles of [[Neuron|neurons]], are surrounded by 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]].
-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.
+== Structure ==
-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.
+The perineurium is composed of [[connective tissue]], which has a distinctly [[lamellar]] arrangement consisting of one to several [[Concentric objects|concentric]] layers. The perineurium is composed of perineurial cells, which are [[epithelioid cell|epithelioid]] [[myofibroblasts]]. Perineurial cells are sometimes referred to as [[myoepithelioid]] due to their [[epithelioid cell|epithelioid]] and [[myofibroblastoid]] properties including [[tight junctions]], [[gap junctions]], [[external laminae]] and contractility. The tight junctions provide selective barrier to chemical substances.
+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.
+==Clinical importance==
+The perineurium, as the epineurium, has a clinical importance following a trauma, like a fracture. A sort of lesion called [[axonotmesis]]<ref>{{cite book|first=Frank|last=Netter|title=Netter's Orthopaedics}}</ref> can happen, where the axon of the nerve is damaged while the integrity of the perineurium and epineurium is preserved. In that case, there will be a loss of neural transmission which will be causing a diminished response in the distal part of the nerve. The axon will be able to regenerate itself at a rate of 3 cm per month, generally indicating a return to a physiological state in roughly three months.
 ==See also==
+* [[Connective tissue in the peripheral nervous system]]
-* [[Nerve fascicle]]
 * [[Endoneurium]]
 * [[Epineurium]]
+* [[Nerve fascicle]]
-*[[Connective tissue in the peripheral nervous system]]
 == References ==
@@ Line 40: / Line 38: @@
 ==External links==
-* {{eMedicineDictionary|Perineurium}}
 * {{OklahomaHistology|1_03}} - "Peripheral nerve"
 * {{UCDavisOrganology|nervous/pns/nerve1/nerve2}} - "PNS, nerve (LM, Low)"
 * {{BUHistology|21401loa}}
-* [http://www.med.howard.edu/anatomy/gas/wk2/images/image2.gif Diagram at Howard]
+* [https://web.archive.org/web/20060929155443/http://www.med.howard.edu/anatomy/gas/wk2/images/image2.gif Diagram at Howard]
-* [http://neuromedia.neurobio.ucla.edu/campbell/nervous/wp_images/182%20endoneurium%20LP.jpg Histology at ucla.edu]
+* [https://web.archive.org/web/20060623132325/http://neuromedia.neurobio.ucla.edu/campbell/nervous/wp_images/182%20endoneurium%20LP.jpg Histology at ucla.edu]
-[[Category:Soft tissue]]
-[[Category:Nervous system]]
-{{neuroscience-stub}}
 {{Nervous tissue}}
+{{Authority control}}
+[[Category:Neurohistology]]