Editing Spinal canal

{{short description|Passage through the vertebral column containing the spinal cord}}
{{Distinguish|Central canal|vertebral foramen|intervertebral foramen}}
{{Infobox anatomy
| Name        = Spinal canal
| Latin       = c. vertebralis
| Image       = Scheme body cavities-en.svg
| Caption     =Spinal cavity shown as part of [[dorsal body cavity]].
| Image2     = Gray82.png
| Caption2   = A typical [[thoracic vertebra]] viewed from above. (Spinal canal is not labeled, but the [[vertebral foramen|foramen]] in the center would make up part of it.)
| System      =
}}

In [[human anatomy]], the '''spinal canal''', '''vertebral canal''' or '''spinal cavity''' is an elongated [[body cavity]] enclosed within the [[neural arch|dorsal bony arch]]es of the [[vertebral column]], which contains the [[spinal cord]], [[spinal root]]s and [[dorsal root ganglia]]. It is a process of the [[dorsal body cavity]] formed by alignment of the [[vertebral foramina]]. Under the vertebral arches, the spinal canal is also covered anteriorly by the [[posterior longitudinal ligament]] and posteriorly by the [[ligamentum flavum]]. The [[potential space]] between these ligaments and the [[dura mater]] covering the spinal cord is known as the [[epidural space]]. [[Spinal nerve]]s exit the spinal canal via the [[intervertebral foramina]] under the corresponding vertebral pedicles.

In humans, the spinal cord gets outgrown by the vertebral column during development into adulthood, and the lower section of the spinal canal is occupied by the [[filum terminale]] and a bundle of spinal nerves known as the [[cauda equina]] instead of the actual spinal cord, which finishes at the [[lumbar spine|L1/L2]] level.

== Structure ==
The vertebral canal is enclosed anteriorly by the vertebral bodies, intervertebral discs, and the [[posterior longitudinal ligament]]; it is enclosed posteriorly by the vertebral laminae and the [[ligamenta flava]]; laterally, it is incompletely enclosed by the [[Pedicle of the vertebral arch|pedicles]] with the interval between two adjacent pedicles on either side creating an [[intervertebral foramen]] (allowing the passage of the [[Spinal nerve|spinal nerves]] and radicular blood vessels).'''<ref name=":02">{{Cite book |last=Sinnatamby |first=Chummy S. |title=Last's Anatomy |publisher= |year=2011 |isbn=978-0-7295-3752-0 |edition=12th |pages=425}}</ref>'''

The vertebral canal progressively narrows inferiorly.'''<ref name=":02" />''' It is wider in the [[Cervical vertebrae|cervical region]] to accommodate the [[cervical enlargement]] of the spinal cord.<ref>{{Citation |last=Kim |first=Hak-Jin |title=Chapter 3 - Radiologic Anatomy of the Spine |date=2010-01-01 |url=http://www.sciencedirect.com/science/article/pii/B9780702029134000033 |work=Minimally Invasive Percutaneous Spinal Techniques |pages=46–57 |editor-last=Kim |editor-first=Daniel H. |access-date=2020-11-03 |place=New York |publisher=W.B. Saunders |language=en |doi=10.1016/b978-0-7020-2913-4.00003-3 |isbn=978-0-7020-2913-4 |editor2-last=Kim |editor2-first=Yong-Chul |editor3-last=Kim |editor3-first=Kyung-Hoon|url-access=subscription }}</ref><ref name="Haran">{{cite web |last1=Haran |first1=Crishan |title=Spinal canal {{!}} Radiology Reference Article {{!}} Radiopaedia.org |url=https://radiopaedia.org/articles/spinal-canal?lang=gb |website=Radiopaedia}}</ref>

=== Contents ===
{{More citations needed|section|date=November 2020}}
The outermost layer of the [[meninges]], the [[dura mater]], is closely associated with the [[arachnoid mater]] which in turn is loosely connected to the innermost layer, the [[pia mater]]. The meninges divide the spinal canal into the [[epidural space]] and the [[subarachnoid space]]. The [[pia mater]] is closely attached to the [[spinal cord]]. A [[subdural space]] is generally only present due to trauma and/or pathological situations. The [[subarachnoid space]] is filled with [[cerebrospinal fluid]] and contains the vessels that supply the [[spinal cord]], namely the [[anterior spinal artery]] and the paired [[posterior spinal arteries]], accompanied by corresponding [[spinal veins]]. The anterior and posterior spinal arteries form [[anastomoses]] known as the '''vasocorona''' of the spinal cord and these supply nutrients to the canal. The [[epidural space]] contains loose fatty tissue, and a network of large, thin-walled blood vessels called the [[internal vertebral venous plexuses]].{{Citation needed|date=June 2023}}

== Clinical significance ==
[[Spinal stenosis]] is a narrowing of the canal which can occur in any region of the spine and can be caused by a number of factors. It may result in [[Myelopathy|cervical myelopathy]]<ref>{{Citation|last1=Lewit|first1=Karel|title=Chapter 3 - Functional anatomy and radiology of the spinal column|date=2010-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780702030567000036|work=Manipulative Therapy|pages=39–85|editor-last=Lewit|editor-first=Karel|place=Edinburgh|publisher=Churchill Livingstone|language=en|doi=10.1016/b978-0-7020-3056-7.00003-6|isbn=978-0-7020-3056-7|access-date=2020-11-03|last2=Ellis|first2=Richard M|editor2-last=Ellis|editor2-first=Richard M|url-access=subscription}}</ref> if the narrowed canal impinges on the spinal cord itself.

Spinal canal [[endoscopy]] can be used to investigate the epidural space, and is an important spinal [[Medical test|diagnostic technique]].<ref>{{Citation|last=Datta|first=Sukdeb|title=Chapter 87 - EPIDURAL ADHESIOLYSIS|date=2009-01-01|url=http://www.sciencedirect.com/science/article/pii/B9781416048367000870|work=Current Therapy in Pain|pages=629–639|editor-last=Smith|editor-first=HOWARD S.|place=Philadelphia|publisher=W.B. Saunders|language=en|doi=10.1016/b978-1-4160-4836-7.00087-0|isbn=978-1-4160-4836-7|access-date=2020-11-03|url-access=subscription}}</ref><ref>{{Citation|last=Saberski|first=Lloyd R.|title=chapter 15 - Spinal Canal Endoscopy|date=2007-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780721603346500194|work=Pain Management|pages=167–178|editor-last=Waldman|editor-first=Steven D.|place=Philadelphia|publisher=W.B. Saunders|language=en|doi=10.1016/b978-0-7216-0334-6.50019-4|isbn=978-0-7216-0334-6|access-date=2020-11-03|editor2-last=Bloch|editor2-first=Joseph I.|url-access=subscription}}</ref>

== History ==
The spinal canal was first described by [[Jean Fernel]].{{Citation needed|date=November 2020}}

==References==
{{reflist}}

==External links==
{{Commons category|Human spinal cord}}
* [http://www.orthorehab.wisc.edu/rehab/interventionalpainprogram/images/spinal_Canalnew2.jpg Diagram at wisc.edu]

{{Bones of torso}}
{{Authority control}}

[[Category:Bones of the thorax]]
[[Category:Bones of the vertebral column]]