Editing Extrapyramidal system

{{Short description|Connection between brain and spinal cord}}
{{More citations needed|date=September 2014}}
{{Infobox brain
| Name            = Extrapyramidal system
| Latin           = systema extrapyramidale
| Image           = Spinal cord tracts - English.svg
| Caption         = Medulla spinalis. (Extrapyramidal tracts are labeled as a group in red, at bottom left.)
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In [[anatomy]], the '''extrapyramidal system''' is a part of the [[motor system]] [[large-scale brain networks|network]] causing involuntary actions.<ref name="Yuan">{{cite journal|last1=Yuan|first1=Rui|last2=Di|first2=Xin|last3=Taylor|first3=Paul A.|last4=Gohel|first4=Suril|last5=Tsai|first5=Yuan-Hsiung|last6=Biswal|first6=Bharat B.|title=Functional topography of the thalamocortical system in human|journal=Brain Structure and Function|date=30 April 2015|doi=10.1007/s00429-015-1018-7|pmid=25924563|volume=221|issue=4|pages=1971–1984|pmc=6363530}}</ref> The system is called ''extrapyramidal'' to distinguish it from the tracts of the motor cortex that reach their targets by traveling through the [[pyramid of medulla oblongata|pyramids]] of the [[medulla oblongata|medulla]]. The [[pyramidal tracts]] ([[corticospinal tract]] and [[corticobulbar tract]]s) may directly innervate motor neurons of the spinal cord or brainstem ([[anterior horn (spinal cord)|anterior (ventral) horn cells]] or certain cranial nerve nuclei), whereas the extrapyramidal system centers on the modulation and regulation (indirect control) of anterior (ventral) horn cells.

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==Extrapyramidal tracts==
The '''extrapyramidal tracts''' are chiefly found in the [[reticular formation]] of the [[pons]] and [[Medulla oblongata|medulla]], and target [[lower motor neuron]]s in the spinal cord that are involved in reflexes, locomotion, complex movements, and postural control. These tracts are in turn modulated by various parts of the central nervous system, including the [[nigrostriatal pathway]], the [[basal ganglia]], the [[cerebellum]], the [[vestibular nuclei]], and different sensory areas of the [[cerebral cortex]]. All of these regulatory components can be considered part of the extrapyramidal system, in that they modulate motor activity without directly innervating motor neurons.

The extrapyramidal tracts include parts of the following:<ref>{{Cite book |title=Physiology |last=Costanzo |first=Linda S. |date=30 July 2010 |publisher=LWW |isbn=978-0781798761}}</ref><ref name="Openstax Anatomy & Physiology attribution">{{CC-notice|cc=by4|url=https://openstax.org/books/anatomy-and-physiology/pages/14-3-motor-responses}} {{cite book|last1=Betts|first1=J Gordon|last2=Desaix|first2=Peter|last3=Johnson|first3=Eddie|last4=Johnson|first4=Jody E|last5=Korol|first5=Oksana|last6=Kruse|first6=Dean|last7=Poe|first7=Brandon|last8=Wise|first8=James|last9=Womble|first9=Mark D|last10=Young|first10=Kelly A|title=Anatomy & Physiology|location=Houston|publisher=OpenStax CNX|isbn=978-1-947172-04-3|date=July 22, 2023|at=14.3 Motor responses}}</ref>
* [[rubrospinal tract]]: Conflicts between the motor commands sent by the cerebrum and body position information provided by the proprioceptors cause the cerebellum to stimulate the [[red nucleus]] of the midbrain. The red nucleus then sends corrective commands to the spinal cord along the rubrospinal tract.
* [[reticulospinal tract]]: connects the [[reticular system]], a diffuse region of gray matter in the brain stem, to the spinal cord. It also contributes to muscle tone and influences autonomic functions.
* [[lateral vestibulospinal tract]]: Connects the brain stem nuclei of the vestibular system with the spinal cord. This allows posture, movement, and balance to be modulated on the basis of equilibrium information provided by the vestibular system.
* [[tectospinal tract]]: This tract projects from the midbrain to the spinal cord and is important for postural movements that are driven by the superior colliculus.

==See also==
* [[List of regions in the human brain]]
* [[Extrapyramidal symptoms]]
* [[Rabbit syndrome]], a rare extrapyramidal side effect
* [[Reticulospinal tract]]
* [[Tectospinal tract]]
* [[Vestibulospinal tract]]

==References==
{{Reflist}}

{{Spinal cord}}
{{Neural tracts}}
{{Authority control}}

{{DEFAULTSORT:Extrapyramidal System}}
[[Category:Central nervous system]]
[[Category:Motor system]]