Spinal nerve

Organization and role

There are usually 31 pairs of spinal nerves. After the roots join, both dorsal and ventral rami carry mixed fibers; dorsal does not therefore mean exclusively sensory.

Clinical relevance and investigation

Injury may combine pain, weakness and sensory changes. Accurate localization requires distinguishing a spinal nerve from a root, plexus or peripheral nerve.

Points to consider

A root, plexus and peripheral nerve are different levels of the nervous system. Limb pain alone cannot distinguish them. The distribution of sensory changes, weakness and altered reflexes helps localize a problem.

Role of TAGMED care

At TAGMED, assessment aims to understand symptoms, history and functional limitations. Manual care and osteopathy, motorized spinal decompression, laser and shockwave have different indications. The term described in this entry is not enough to select any of these modalities. Their relevance, limitations and possible contraindications should be discussed in relation to diagnosis and individual goals.

Related concepts and distinctions

These concepts belong to the same field, but are not synonyms.

• Dorsal root — Bundle of afferent fibers carrying sensory information toward the spinal cord, with neuronal cell bodies located in the dorsal root ganglion.
• Ventral root — Bundle of efferent fibers leaving the spinal cord, including somatic motor axons and, at certain levels, preganglionic autonomic fibers.
• Dorsal ramus of the spinal nerve — Posterior mixed branch of a spinal nerve supplying deep back muscles, some joints and part of the skin of the back.

Medical references

1. OpenStax, Rice University. Anatomy and Physiology 2e — The Peripheral Nervous System.
2. Radiological Society of North America. RadLex Radiology Lexicon — terminology resource.

References document the topic; their inclusion does not imply endorsement of TAGMED services by those organizations.