Spinalkanals

The spinal canal, also called the vertebral canal, is a protective passage within the vertebral column that houses the spinal cord and the cauda equina. It is formed by the vertebral foramina of the adjacent vertebrae and is lined by the meninges, with cerebrospinal fluid circulating in the subarachnoid space.

The canal extends from the foramen magnum at the base of the skull to the sacral region of the spine. In adults, the spinal cord typically ends at the level of the first two lumbar vertebrae (the conus medullaris); below this point, the cauda equina consists of nerve roots that descend to their exit foramina. The dura mater forms a dural sac around the cauda equina, and the subarachnoid space within the sac contains cerebrospinal fluid. An epidural space lies between the dura and the inner surface of the vertebral canal.

Clinical significance arises from variations in canal size. Spinal stenosis refers to a narrowing of the spinal canal, which can result from degenerative changes, disc herniation, thickened ligaments, or bone spurs. Narrowing may compress the spinal cord or nerve roots, causing pain, numbness, weakness, or neurogenic claudication. Other conditions such as trauma, tumors, infections, or inflammatory diseases can also affect canal integrity. Diagnosis is commonly achieved with magnetic resonance imaging (MRI) or computed tomography (CT), and management ranges from conservative therapies to surgical decompression (for example, laminectomy or discectomy) depending on symptoms and structural findings.

Size and shape of the spinal canal vary along the spine. The cervical region generally has a relatively larger canal, whereas the thoracic region is comparatively narrower; congenital stenosis or age-related changes can influence canal dimensions at any level.