Ligamentous apparatus

Numerous ligaments provide for a stabilization of the bony spine. These include the anterior and posterior longitudinal ligaments (Lig. longitudinale anterius and posterius), which run along the entire spinal column from cranial to caudal, the yellow ligaments (Ligamenta flava), which connect the adjacent vertebral arches, and the ligaments between the spinous processes (Ligamenta interspinalia).

Spinal cord

The spinal cord runs through the spinal canal, which is formed by the individual vertebral holes (Foramina vertebralia) in a caudal direction, and here it releases a nerve cord (the spinal nerve) to the right and left at each vertebral body. This spinal nerve runs through the intervertebral holes (Foramina intervertebralia) and thus leaves the spinal canal. There are 31 pairs of spinal nerves.

8 cervical (belonging to the cervical spine), 12 thoracic (belonging to the thoracic spine), 5 lumbar (belonging to the lumbar spine), 5 sacral (belonging to the sacral spine of the sacrum) and 1 coccygal (belonging to the coccyx), which is only rudimentarily developed in humans. In the region of the cervical spine, the first spinal nerve (C1) emerges above the first cervical vertebrae (HWK 1), so that in the region of the cervical spine the spinal nerve emerges above its associated vertebral body. However, the fact that there are 8 cervical spinal nerves and only 7 cervical vertebral bodies changes this pattern with the 8th spinal nerve exiting below the 7th cervical vertebrae.

Thus, the 1st thoracic spinal nerve (Th 1) emerges below its associated vertebral body (BWK 1).The spinal cord as such ends at the level of the 1st lumbar vertebral body, while the spinal nerves run even further down on their way to their assigned exit openings. This bundle of spinal nerves, which no longer contains the spinal cord itself, is called cauda equina. When taking cerebral fluid in the area of the back (lumbar puncture or liquor puncture), it is therefore possible to insert a needle from the 2nd lumbar vertebra (but usually between the 3rd and 4th lumbar vertebra) without the risk of damaging the spinal cord. The cauda equina running there is flexible and can avoid the needle tip.