seljaajuõõnsus

Seljaajuõõnsus, also known as the spinal canal or vertebral canal, is a hollow space within the vertebral column that encloses and protects the spinal cord. This continuous cavity is formed by the stacked vertebrae, specifically by the vertebral arches that meet in the midline. Each vertebra contributes to the formation of this canal, providing a protective bony tunnel for the delicate neural tissues.

The primary function of the seljaajuõõnsus is to safeguard the spinal cord, which is a crucial component of the central nervous system. The spinal cord transmits nerve signals between the brain and the rest of the body, and its protection is vital for proper bodily function and sensation. Within the seljaajuõõnsus, the spinal cord is further cushioned by cerebrospinal fluid and meninges, which are protective membranes.

The structure of the seljaajuõõnsus varies slightly along its length. It is wider in the cervical and lumbar regions, accommodating the enlargements of the spinal cord that give rise to the brachial and lumbosacral plexuses, respectively, which innervate the limbs. Inferiorly, the seljaajuõõnsus tapers to a point called the conus medullaris, usually around the level of the first or second lumbar vertebra. Below this point, the canal contains the cauda equina, a bundle of nerve roots that extend down before exiting the column. Any narrowing or compromise of the seljaajuõõnsus can lead to compression of the spinal cord or nerve roots, resulting in neurological deficits.