Editing Internal capsule (section)

{{Short description|White matter structure of the brain}}
{{Infobox brain
| Name            = Internal capsule
| Latin           = capsula interna
| Image           = File:Telencephalon-Horiconatal.jpg
| Caption         = Horizontal section of right cerebral hemisphere. (Capsula interna labeled at upper left.)
| Image2          = File:Gray764.png
| Caption2        = The motor tract.
| IsPartOf        =
| Components      =
| Artery          =
| Vein            =
}}
The '''internal capsule''' is a paired [[white matter]] structure, as a two-way [[nerve tract|tract]], carrying [[afferent nerve fiber|ascending]] and [[efferent nerve fiber|descending]] [[axon|fibers]], to and from the [[cerebral cortex]].  The internal capsule is situated in the [[Anatomical terms of location#Medial and lateral|inferomedial]] part of each [[cerebral hemisphere]] of the [[brain]]. It carries information past the subcortical [[basal ganglia]]. As it courses it separates the [[caudate nucleus]] and the [[thalamus]] from the [[putamen]] and the [[globus pallidus]]. It also separates the caudate nucleus and the putamen in the [[dorsal striatum]], a brain region involved in motor and reward pathways.<ref name="Emos-2022"/>

The internal capsule is V-shaped in transection forming an anterior and posterior limb, with the angle between them called the genu.

The [[corticospinal tract]] constitutes a large part of the internal capsule, carrying motor information from the [[primary motor cortex]] to the [[lower motor neurons]] in the [[spinal cord]]. Above the basal ganglia the corticospinal tract is a part of the [[corona radiata]]. Below the basal ganglia the tract is called [[cerebral crus]] (a part of the [[cerebral peduncle]]) and below the [[pons]] it is referred to as the corticospinal tract.<ref>{{Cite book |last1=Schmahmann |first1=Jeremy D. |url=https://books.google.com/books?id=QIZ668QEH0wC&q=%22Internal+capsule%22+-wikipedia |title=Fiber Pathways of the Brain |last2=Schmahmann |first2=Jeremy |last3=Pandya |first3=Deepak |date=2009-02-11 |publisher=Oxford University Press, USA |isbn=978-0-19-538826-8 |language=en}}</ref><ref>{{Cite book |last=Standring |first=Susan |url=https://books.google.com/books?id=b7FVCgAAQBAJ&dq=%22Internal+capsule%22+-wikipedia&pg=PA395-IA1 |title=Gray's Anatomy E-Book: The Anatomical Basis of Clinical Practice |date=2015-09-25 |publisher=Elsevier Health Sciences |isbn=978-0-7020-6851-5 |language=en}}</ref>