{{refimprove|date=November 2025}} {{Short description|Part of the spinal cord}} {{Infobox anatomy | Name = Dorsal root of spinal nerve | Latin = radix posterior nervi spinalis | Image = spinal nerve.svg | Caption = The formation of the spinal nerve from the dorsal and ventral roots | Image2 = | Caption2 = | System = | Precursor = }} The '''dorsal root of spinal nerve''' (or '''posterior root of spinal nerve''' or '''sensory root'''){{fact|date=September 2025}} is one of two "roots" which emerge from the [[spinal cord]]. It emerges directly from the spinal cord and travels to the [[dorsal root ganglion]]. Nerve fibres with the [[Ventral root of spinal nerve|ventral root]] then combine to form a [[spinal nerve]]. The dorsal root transmits [[Somatosensory system|sensory]] information, forming the [[afferent nerve|afferent]] sensory root of a spinal nerve.
==Structure== The root emerges from the [[Posterior (anatomy)|posterior]] part of the [[spinal cord]] and travels to the [[dorsal root ganglion]]. The dorsal root ganglia contain the [[pseudounipolar neuron|pseudo-unipolar]] [[cell bodies]] of the [[nerve]] fibres which travel from the ganglia through the root into the spinal cord.
The [[Lateral (anatomy)|lateral]] division of the dorsal root contains lightly [[myelin]]ated and unmyelinated fibres of small diameter.{{Citation needed|date=July 2019}} These carry pain and temperature sensation. These fibers cross through the [[anterior white commissure]] to form the [[anterolateral system]] in the [[lateral funiculus]].
The medial division of the dorsal root contains myelinated fibres of larger diameter{{Citation needed|date=July 2019}}. These transmit information of discriminative touch, pressure, vibration, and conscious [[proprioception]] originating from spinal levels [[Cervical spinal nerve 2|C2]] through [[Sacral spinal nerve 5|S5]]. These fibers are pushed in towards the posterior median sulcus to form the [[gracile fasciculus]] and the cuneate fasciculus of the [[posterior column–medial lemniscus pathway]]. If the dorsal root of a spinal nerve were severed, it would lead to numbness in certain areas of the body.
==Additional images== <gallery> File:Cervical vertebra english.png|[[Cervical vertebra]] File:Medulla spinalis - Section - English.svg|Medulla spinalis File:Gray675.png|A spinal nerve with its anterior and posterior roots File:Gray759.png|The sensory tract File:Gray770-en.svg|Diagrammatic transverse section of the medulla spinalis and its membranes File:Gray796.png|A portion of the spinal cord, showing its right lateral surface. The dura is opened and arranged to show the nerve roots. File:Gray799.svg|Scheme showing structure of a typical spinal nerve </gallery>
==References== {{Reflist}}
==External links== * {{SUNYAnatomyFigs|02|04|06}} - "Superior view of a section through the spinal cord within the [[vertebral foramen]]." * {{AnatomyAtlasesMicroscopic|06|114}} - "Spinal Root Nerve Fibers" * [http://ccdb.ucsd.edu/sand/main?stype=lite&keyword=dorsal%20root&Submit=Go&event=display&start=1 Dorsal root - Cell Centered Database]
{{Nervous tissue}} {{Authority control}}
[[Category:Back anatomy]] [[Category:Peripheral nervous system]] [[Category:Thoracic nerves]]