Nerve root

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The nerve root is the name given to the (radicular) nerve fibers entering and exiting the spinal cord . The nerve cell bodies ( perikarya or somata ) belonging to the anterior root are also known as root cells . Each segment of the spine has two nerve roots on both sides, each of which unites in the intervertebral canal to form a spinal nerve (spinal cord nerve).

The afferents (supplying nerve fibers), which carry sensitive information to the spinal cord, pass through the posterior nerve root ( radix posterior , in animals radix dorsalis ) . Their cell bodies lie outside the spinal cord in the spinal ganglion ( ganglion spinal ).

The efferents (nerve fibers leading away) emerge from the spinal cord through the anterior nerve root ( radix anterior , in animals radix ventralis ) . This nerve root contains motor nerve fibers whose cell bodies are located in the anterior horn of the gray matter of the spinal cord, and in some parts of the spinal cord also fibers of the autonomic nervous system whose cell bodies are located in the middle part ( pars intermedia ) of the gray matter.

The knowledge of the functional separation of the two spinal nerve roots goes back to Charles Bell and François Magendie ( Bell-Magendie law ). An area of ​​the nerve root near its entry into the spinal cord is viewed as the transition zone between the peripheral and central nervous system ( Redlich-Obersteiner zone ).

See also