| Spinal canal | |
|---|---|
 Spinal cavity shown as part ofdorsal body cavity. | |
 A typicalthoracic vertebra viewed from above. (Spinal canal is not labeled, but theforamen in the center would make up part of it.) | |
| Details | |
| Identifiers | |
| Latin | c. vertebralis |
| MeSH | D013115 |
| TA98 | A02.2.00.009 |
| TA2 | 1009 |
| FMA | 9680 |
| Anatomical terminology | |
Inhuman anatomy, thespinal canal,vertebral canal orspinal cavity is an elongatedbody cavity enclosed within thedorsal bony arches of thevertebral column, which contains thespinal cord,spinal roots anddorsal root ganglia. It is a process of thedorsal body cavity formed by alignment of thevertebral foramina. Under the vertebral arches, the spinal canal is also covered anteriorly by theposterior longitudinal ligament and posteriorly by theligamentum flavum. Thepotential space between these ligaments and thedura mater covering the spinal cord is known as theepidural space.Spinal nerves exit the spinal canal via theintervertebral 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 thefilum terminale and a bundle of spinal nerves known as thecauda equina instead of the actual spinal cord, which finishes at theL1/L2 level.
The vertebral canal is enclosed anteriorly by the vertebral bodies, intervertebral discs, and theposterior longitudinal ligament; it is enclosed posteriorly by the vertebral laminae and theligamenta flava; laterally, it is incompletely enclosed by thepedicles with the interval between two adjacent pedicles on either side creating anintervertebral foramen (allowing the passage of thespinal nerves and radicular blood vessels).[1]
The vertebral canal progressively narrows inferiorly.[1] It is wider in thecervical region to accommodate thecervical enlargement of the spinal cord.[2][3]
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The outermost layer of themeninges, thedura mater, is closely associated with thearachnoid mater which in turn is loosely connected to the innermost layer, thepia mater. The meninges divide the spinal canal into theepidural space and thesubarachnoid space. Thepia mater is closely attached to thespinal cord. Asubdural space is generally only present due to trauma and/or pathological situations. Thesubarachnoid space is filled withcerebrospinal fluid and contains the vessels that supply thespinal cord, namely theanterior spinal artery and the pairedposterior spinal arteries, accompanied by correspondingspinal veins. The anterior and posterior spinal arteries formanastomoses known as thevasocorona of the spinal cord and these supply nutrients to the canal. Theepidural space contains loose fatty tissue, and a network of large, thin-walled blood vessels called theinternal vertebral venous plexuses.[citation needed]
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 incervical myelopathy[4] if the narrowed canal impinges on the spinal cord itself.
Spinal canalendoscopy can be used to investigate the epidural space, and is an important spinaldiagnostic technique.[5][6]
The spinal canal was first described byJean Fernel.[citation needed]
