Thecentral canal(also known asspinal foramenorependymal canal) is thecerebrospinal fluid-filled space that runs through thespinal cord.[1]The central canal lies below and is connected to theventricular systemof thebrain,from which it receives cerebrospinal fluid, and shares the sameependymallining. The central canal helps to transport nutrients to the spinal cord as well as protect it by cushioning the impact of a force when the spine is affected.
| Central canal of spinal cord | |
|---|---|
 Cross-section through cervical spinal cord. | |
 | |
| Details | |
| Location | Centre of thespinal cord |
| Identifiers | |
| Latin | canalis centralis medullae spinalis |
| TA98 | A14.1.02.019 |
| TA2 | 6127 |
| FMA | 78497 |
| Anatomical terminology | |
The central canal represents the adult remainder of the central cavity of theneural tube.It generally occludes (closes off) with age.[2]
Structure
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The central canal below at theventricular systemof thebrain,beginning at a region called theobexwhere thefourth ventricle,a cavity present in the brainstem, narrows.
The central canal is located in theanteriorthird of the spinal cord in thecervicalandthoracicregions. In thelumbar spineit enlarges and is located more centrally. At theconus medullaris,where the spinal cord tapers, it is located moreposteriorly.
Terminal ventricle
editTheterminal ventricle(ventriculus terminalis,fifth ventricleorampulla caudalis) is the widest part of the central canal of thespinal cordthat is located at or near theconus medullaris.[3][unreliable source?]It was described by Stilling in 1859 and Krause in 1875.[4]Krause introduced the term fifth ventricle after observation of normalependymal cells.[4]The central canal expands as a fusiform terminal ventricle, and approximately 8–10 mm in length in the conus medullaris (or conus terminalis).[5]Although the terminal ventricle is visible in the fetus and children, it is usually absent in adults.[3]
Sometimes, the terminal ventricle is observed byMRIorultrasoundin children less than 5 years old.[6]
Microanatomy
editThe central canal shares the sameependymallining as the ventricular system of the brain.
The canal is lined byciliated,column-shaped cells,outside of which is a band of gelatinous substance, called thesubstantia gelatinosa of Rolandoalsosubstantia gelatinosa centralisorcentral gelatinous substance of spinal cord.This gelatinous substance consists mainly ofneuroglia,but contains a few nerve cells and fibers; it is traversed by processes from the deep ends of the columnar ciliated cells which line the central canal.
Development
editThe central canal represents the adult remainder of the central cavity of theneural tube.It generally occludes (closes off) with age.[2]
Function
editThe central canal carriescerebrospinal fluid(CSF), which it receives from theventricular systemof the brain. The central canal helps to transport nutrients to the spinal cord as well as protect it by cushioning the impact of a force when the spine is affected.
Clinical significance
editSyringomyeliais a disease caused by the blockage of the central canal. Blockage of the central canal usually occurs at the lower cervical and upper thoracic levels. This typically damageswhite matterfibers that cross inanterior white commissure,leading to the loss of temperature, pain, and motor function at the affected levels on side opposite to the damage.
Other relevant conditions include:
- Spina bifida
- Arnold-Chiari syndrome
- Spinal tumor
- Myelomeningocele
- Syringomyelia
- Hydromyelia.In hydromyelia, a dilation of the central canal of the spinal cord is caused by an increase of cerebrospinal fluid.[7]
- Syringohydromyelia(i.e., both Syringomyelia and Hydromyelia)[7]
- Tethered cord
In some cases, the terminal ventricle may cause clinical symptoms due to its expansion.
References
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This article incorporates text in thepublic domainfrompage 753of the 20th edition ofGray's Anatomy(1918)
- ^Saker, Erfanul; Henry, Brandon M; Tomaszewski, Krzysztof A; Loukas, Marios; Iwanaga, Joe; Oskouian, Rod J; Tubbs, R. Shane (2016)."The Human Central Canal of the Spinal Cord: A Comprehensive Review of its Anatomy, Embryology, Molecular Development, Variants, and Pathology".Cureus.8(12): e927.doi:10.7759/cureus.927.ISSN2168-8184.PMC5234862.PMID28097078.
- ^ab"ventriculus terminalis".radsource.us.July 2008.
- ^abLiccardo G, Ruggeri F, De Cerchio L, Floris R, Lunardi P (June 2005)."Fifth ventricle: an unusual cystic lesion of the conus medullaris".Spinal Cord.43(6): 381–4.doi:10.1038/sj.sc.3101712.PMID15655569.
- ^Williams & Warwick. Gray's Anatomy.THIRTY-SEVENTH EDITION.ISBN0 443 04177 6[page needed]
- ^Celli P, D'Andrea G, Trillò G, Roperto R, Acqui M, Ferrante L (March 2002). "Cyst of the medullary conus: malformative persistence of terminal ventricle or compressive dilatation?".Neurosurgical Review.25(1–2): 103–6.doi:10.1007/s10143-001-0203-8.PMID11954762.S2CID2214756.
- ^ab"imaging in syringohydromyelia".emedicine.medscape.2018-04-25.
Tomsick T, Peak E, Wang L: Fluid-Signal Structures in the Cervical Spinal Cord on MRI: Anterior Median Fissure vs. Central Canal. AJNR 2017; 38:840–45
Tomsick T, Wang L, Zuccarello M, Ringer AJ. Fluid-signal structures in the cervical spinal cord on MRI in Chiari patients: Central canal or anterior median fissure? AJNR Am J Neuroradiol. 2021 Apr;42(4):801-806. doi: 10.3174/ajnr.A7046. Epub 2021 Mar 11.PMID: 33707286