Nerve Root | Anatomy of the spine

Nerve Root

Nerve roots are fibers that enter or exit the spinal cord. On each section of the spinal column (segment) there are 2 nerve roots on the right and left side, one at the back and one at the front. The front roots transmit motor commands from the brain to the muscles, while the rear ones transmit sensitive information such as pain or touch from the body to the brain.

The 2 roots of one side unite in the spinal canal to form a spinal nerve (spinal nerve). On each side, a spinal nerve leaves the spinal canal through an intervertebral hole. Of the total of 7 cervical vertebrae, the first (atlas) and second (axis) deviate most from the basic shape of the vertebrae.

They are constructed in such a way that they can both take the main load of the head and allow movement in three degrees of freedom, corresponding to a ball joint. The first cervical vertebraAtlas“, named after the Greek mythology, lies directly under the occipital hole (Foramen magnum) of the skull, bears its entire load and includes the tooth of the second cervical vertebra, the twister (Axis). The remaining five cervical vertebrae (cervical spine) have a relatively small and, in top view, almost cubic vertebral body and a large, triangular vertebral hole in which the nerve tracts coming from the skull continue as spinal cord.

As a special anatomical feature, the transverse processes of the cervical spine are split, thus forming a canal that leads to a brain-supplying artery (arteria vertebralis) on the left and right. The upper surface of the transverse process exhibits a deep, wide channel from the third cervical vertebrae onwards, through which the respective spinal nerve protrudes outwards through the intervertebral hole. Thus eight nerve bundles emerge on each side in the area of the cervical spine.The upper four form the cervical nerve plexus, which innervates the neck muscles and the diaphragm, the most important respiratory muscle.

If an injury occurs above these spinal cord segments, for example in a car accident, independent breathing is no longer possible. Together with the first of the thoracic spine, the lower four nerve bundles form the brachial nerve plexus, which is responsible for the motor functions of the arm and chest muscles and the skin areas in these areas. The seventh cervical vertebra can be quickly identified from the outside through the spinous process which protrudes backwards. This gave it its own name: Vertebra prominens. The articular processes connect the individual vertebrae with each other in an upward and downward articulated manner.