Central canal

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Central canal of spinal cord
Medulla spinalis - Section - English.svg
Cross-section through cervical spinal cord.
Medulla spinalis - Substantia grisea - English.svg
Details
LocationCentre of the spinal cord
Identifiers
Latin canalis centralis medullae spinalis
TA98 A14.1.02.019
TA2 6127
FMA 78497
Anatomical terminology

The central canal (also known as spinal foramen or ependymal canal [1] ) is the cerebrospinal fluid-filled space that runs through the spinal cord. [1] The central canal lies below and is connected to the ventricular system of the brain, from which it receives cerebrospinal fluid, and shares the same ependymal lining. 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.

Contents

The central canal represents the adult remainder of the central cavity of the neural tube. It generally occludes (closes off) with age. [2]

Structure

Cross section of central canal Gray667.png
Cross section of central canal

The central canal below at the ventricular system of the brain, beginning at a region called the obex where the fourth ventricle, a cavity present in the brainstem, narrows.

The central canal is located in the anterior third of the spinal cord in the cervical and thoracic regions. In the lumbar spine it enlarges and is located more centrally. At the conus medullaris, where the spinal cord tapers, it is located more posteriorly .

Terminal ventricle

The terminal ventricle (ventriculus terminalis, fifth ventricle or ampulla caudalis) is the widest part of the central canal of the spinal cord that is located at or near the conus 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 normal ependymal 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 by MRI or ultrasound in children less than 5 years old. [6]

Microanatomy

The central canal shares the same ependymal lining as the ventricular system of the brain.

The canal is lined by ciliated, column-shaped cells, outside of which is a band of gelatinous substance, called the substantia gelatinosa centralis (or central gelatinous substance of spinal cord). This gelatinous substance consists mainly of neuroglia, 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.

The substantia gelatinosa of Rolando is located more dorsally.[ clarification needed ]

Development

The central canal represents the adult remainder of the central cavity of the neural tube. It generally occludes (closes off) with age. [2]

Function

The central canal carries cerebrospinal fluid (CSF), which it receives from the ventricular system of 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

Syringomyelia is 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 damages white matter fibers that cross in anterior 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:

In some cases, the terminal ventricle may cause clinical symptoms due to its expansion.

Related Research Articles

<span class="mw-page-title-main">Cerebrospinal fluid</span> Clear, colorless bodily fluid found in the brain and spinal cord

Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.

<span class="mw-page-title-main">Syringomyelia</span> Disorder in which a cyst forms in the spinal cord

Syringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. Often, syringomyelia is used as a generic term before an etiology is determined. This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in loss of feeling, paralysis, weakness, and stiffness in the back, shoulders, and extremities. Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. It may also lead to a cape-like bilateral loss of pain and temperature sensation along the upper chest and arms. The combination of symptoms varies from one patient to another depending on the location of the syrinx within the spinal cord, as well as its extent.

<span class="mw-page-title-main">Ventricular system</span> Structures containing cerebrospinal fluid

In neuroanatomy, the ventricular system is a set of four interconnected cavities known as cerebral ventricles in the brain. Within each ventricle is a region of choroid plexus which produces the circulating cerebrospinal fluid (CSF). The ventricular system is continuous with the central canal of the spinal cord from the fourth ventricle, allowing for the flow of CSF to circulate.

<span class="mw-page-title-main">Pia mater</span> Delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord

Pia mater, often referred to as simply the pia, is the delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord. Pia mater is medieval Latin meaning "tender mother". The other two meningeal membranes are the dura mater and the arachnoid mater. Both the pia and arachnoid mater are derivatives of the neural crest while the dura is derived from embryonic mesoderm. The pia mater is a thin fibrous tissue that is permeable to water and small solutes. The pia mater allows blood vessels to pass through and nourish the brain. The perivascular space between blood vessels and pia mater is proposed to be part of a pseudolymphatic system for the brain. When the pia mater becomes irritated and inflamed the result is meningitis.

<span class="mw-page-title-main">Fourth ventricle</span> One of four central brain cavities filled with cerebrospinal fluid

The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ventricle. The fourth ventricle extends from the cerebral aqueduct to the obex, and is filled with cerebrospinal fluid (CSF).

<span class="mw-page-title-main">Septum pellucidum</span> Thin membrane between the lateral ventricles of the brain

The septum pellucidum is a thin, triangular, vertical double membrane separating the anterior horns of the left and right lateral ventricles of the brain. It runs as a sheet from the corpus callosum down to the fornix.

<span class="mw-page-title-main">Ependymoma</span> Medical condition

An ependymoma is a tumor that arises from the ependyma, a tissue of the central nervous system. Usually, in pediatric cases the location is intracranial, while in adults it is spinal. The common location of intracranial ependymomas is the fourth ventricle. Rarely, ependymomas can occur in the pelvic cavity.

<span class="mw-page-title-main">Neuromere</span>

Neuromeres are distinct groups of neural crest cells, forming segments in the neural tube of the early embryonic development of the brain. There are three classes of neuromeres in the central nervous system – prosomeres, mesomeres and rhombomeres that will develop the forebrain, midbrain, and hindbrain respectively.

<span class="mw-page-title-main">Ependyma</span> Lining of the ventricular system of the brain

The ependyma is the thin neuroepithelial lining of the ventricular system of the brain and the central canal of the spinal cord. The ependyma is one of the four types of neuroglia in the central nervous system (CNS). It is involved in the production of cerebrospinal fluid (CSF), and is shown to serve as a reservoir for neuroregeneration.

<span class="mw-page-title-main">Lateral ventricles</span> Two largest ventricles in each cerebral hemisphere

The lateral ventricles are the two largest ventricles of the brain and contain cerebrospinal fluid. Each cerebral hemisphere contains a lateral ventricle, known as the left or right lateral ventricle, respectively.

<span class="mw-page-title-main">Subarachnoid cisterns</span> Spaces around the brain filled with cerebrospinal fluid

The subarachnoid cisterns are spaces formed by openings in the subarachnoid space, an anatomic space in the meninges of the brain. The space is situated between the two meninges, the arachnoid mater and the pia mater. These cisterns are filled with cerebrospinal fluid (CSF).

<span class="mw-page-title-main">Conus medullaris</span> Lower part of the spinal cord

The conus medullaris or conus terminalis is the tapered, lower end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is usually not well defined, however, its corresponding spinal cord segments are usually S1–S5.

<span class="mw-page-title-main">Cranial cavity</span> Space inside the skull formed by eight cranial bones known as the neurocranium

The cranial cavity, also known as intracranial space, is the space within the skull that accommodates the brain. The skull minus the mandible is called the cranium. The cavity is formed by eight cranial bones known as the neurocranium that in humans includes the skull cap and forms the protective case around the brain. The remainder of the skull is called the facial skeleton. Meninges are protective membranes that surround the brain to minimize damage to the brain in the case of head trauma. Meningitis is the inflammation of meninges caused by bacterial or viral infections.

<span class="mw-page-title-main">Anterior median fissure of spinal cord</span>

The anterior median fissure of the spinal cord is a deep midline groove of the anterior/ventral spinal cord. It divides the white matter of the anterior spinal cord nearly in two. The spinal pia mater extends into the fissure to line the surfaces of the spinal cord.

<span class="mw-page-title-main">Tela choroidea</span>

The tela choroidea is a region of meningeal pia mater that adheres to the underlying ependyma, and gives rise to the choroid plexus in each of the brain’s four ventricles. Tela is Latin for woven and is used to describe a web-like membrane or layer. The tela choroidea is a very thin part of the loose connective tissue of pia mater overlying and closely adhering to the ependyma. It has a rich blood supply. The ependyma and vascular pia mater – the tela choroidea, form regions of minute projections known as a choroid plexus that projects into each ventricle. The choroid plexus produces most of the cerebrospinal fluid of the central nervous system that circulates through the ventricles of the brain, the central canal of the spinal cord, and the subarachnoid space. The tela choroidea in the ventricles forms from different parts of the roof plate in the development of the embryo.

A syrinx is a rare, fluid-filled neuroglial cavity within the spinal cord (syringomyelia), in the brain stem (syringobulbia), or in the nerves of the elbow, usually in a young age.

<span class="mw-page-title-main">Diastematomyelia</span> Birth defect in which part of the spinal cord is split

In neurology, diastematomyelia is a congenital disorder in which a part of the spinal cord is split, usually at the level of the upper lumbar vertebra in the longitudinal (sagittal) direction. Females are affected much more commonly than males. This condition occurs in the presence of an osseous, cartilaginous or fibrous septum in the central portion of the spinal canal which then produces a complete or incomplete sagittal division of the spinal cord into two hemicords. When the split does not reunite distally to the spur, the condition is referred to as diplomyelia, which is true duplication of the spinal cord.

<span class="mw-page-title-main">Spinal cord</span> Long, tubular central nervous system structure in the vertebral column

The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system.

The rostral neuropore or anterior neuropore is a region corresponding to the opening of the embryonic neural tube in the anterior portion of the developing prosencephalon. The central nervous system develops from the neural tube, which initially starts as a plate of cells in the ectoderm and this is called the neural plate, the neural plate then undergoes folding and starts closing from the center of the developing fetus, this leads to two open ends, one situated cranially/rostrally and the other caudally. Bending of the neural plate begins on day 22, and the cranial neuropore closes on day 24. giving rise to the lamina terminalis of the brain.

Reissner's fiber(named after Ernst Reissner) is a fibrous aggregation of secreted molecules extending from the subcommissural organ (SCO) through the ventricular system and central canal to the terminal ventricle, a small ventricle-like structure near the end of the spinal cord. In vertebrates, Reissner's fiber is formed by secretions of SCO-spondin from the subcommissural organ into the ventricular cerebrospinal fluid. Reissner's fiber is highly conserved, and present in the central canal of all chordates. In cephalochordates, Reissner's fiber is produced by the ventral infundibular organ, as opposed to the dorsal SCO.

References

PD-icon.svgThis article incorporates text in the public domain from page 753 of the 20th edition of Gray's Anatomy (1918)

  1. 1 2 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 . ISSN   2168-8184. PMC   5234862 . PMID   28097078.
  2. 1 2 "ventriculus terminalis". radsource.us. July 2008.
  3. 1 2 Liccardo 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 . PMID   15655569.
  4. ↑ Williams & Warwick. Gray's Anatomy .THIRTY-SEVENTH EDITION. ISBN   0 443 04177 6 [ page needed ]
  5. ↑ 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. PMID   11954762. S2CID   2214756.
  6. 1 2 "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

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