Internal capsule

Internal capsule
Horizontal section of right cerebral hemisphere. (Capsula interna labeled at upper left.)
The motor tract.
Details
Identifiers
Latincapsula interna
MeSHD020772
NeuroNames198
NeuroLex IDbirnlex_1659
TA98A14.1.09.524
TA25576
FMA61950
Anatomical terms of neuroanatomy

The internal capsule is a paired white matter structure, as a two-way tract, carrying ascending and descending fibers, to and from the cerebral cortex. The internal capsule is situated in the 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.[1]

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.[2][3]

  1. ^ Cite error: The named reference Emos-2022 was invoked but never defined (see the help page).
  2. ^ Schmahmann, Jeremy D.; Schmahmann, Jeremy; Pandya, Deepak (2009-02-11). Fiber Pathways of the Brain. Oxford University Press, USA. ISBN 978-0-19-538826-8.
  3. ^ Standring, Susan (2015-09-25). Gray's Anatomy E-Book: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences. ISBN 978-0-7020-6851-5.