dorsal root

Posterior root of spinal nerve
The formation of the spinal nerve from the dorsal and ventral roots
Latin	radix posterior
Gray's	subject #208 916
MeSH	Dorsal+Roots

In anatomy and neurology, the dorsal root (or posterior root) is the afferent sensory root of a spinal nerve.

At the distal end of the dorsal root is the dorsal root ganglion, which contains the neuron cell bodies of the nerve fibres conveyed by the root.

If the dorsal root of a spinal nerve were severed it would lead to numbness in certain areas of the body.

The lateral division of the dorsal root contains lightly myelinated and unmyelinated axons of small diameter. These transmit pain and temperature sensation from the body. These fibers cross through the anterior white commissure to form the Anterior lateral system in the lateral funiculus.

The medial division of the dorsal root contains myelinated axons of larger diameter. These transmit information of discriminative touch, pressure, vibration, and conscious proprioception originating from spinal levels C2 through S5. These fibers are pushed in towards the posterior medial sulcus to form the fasciculus gracilis and the fasciculus cuneatus.

Additional images

Cervical vertebra	Medulla spinalis	A spinal nerve with its anterior and posterior roots.	The sensory tract.
Diagrammatic transverse section of the medulla spinalis and its membranes.	A portion of the spinal cord, showing its right lateral surface. The dura is opened and arranged to show the nerve roots.	Scheme showing structure of a typical spinal nerve.

See also

• Ventral root

External links

• SUNY Figs 02:04-06 - "Superior view of a section through the spinal cord within the vertebral foramen."
• Anatomy Atlases - Microscopic Anatomy, plate 06.114 - "Spinal Root Nerve Fibers"
• Dorsal Root - Cell Centered Database

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