Internal capsule 547735 224604145 2008-07-09T16:49:41Z 79.71.62.155 /* Fibers */ {{Infobox Brain| Name = {{PAGENAME}} | Latin = capsula interna | GraySubject = 189 | GrayPage = 836 | Image = Telencephalon-Horiconatal.jpg | Caption = Horizontal section of right cerebral hemisphere. (Capsula interna labeled at upper left.) | Image2 = Gray764.png | Caption2 = The motor tract. | IsPartOf = | Components = | Artery = | Vein = | BrainInfoType = hier | BrainInfoNumber = 180 | MeshName = | MeshNumber = | DorlandsPre = c_07 | DorlandsSuf = 12211417 | }} The '''internal capsule''' is an area of [[white matter]] in the [[brain]] that separates the [[caudate nucleus]] and the [[thalamus]] from the [[lenticular nucleus]]. The internal capsule contains both ascending and descending axons. It consists of [[axon]]al fibres that run between the [[cerebral cortex]] and the [[pyramids of the medulla]]. ==Components== The internal capsule is V-shaped when cut both ''coronally'' (on the same plane as the face) and ''horizontally''/''transversely'' (the same plane as the brim of a [[top hat]]). When cut horizontally: * the bend in the V is called the "[[Genu_of_the_internal_capsule|genu]]". * the part in front of the genu is the "[[anterior limb]]". or ''crus anterius''. * the part behind the genu is called the "[[posterior limb]]" or ''crus posterius''. There is also a ''retrolenticular'' and a ''sublenticular'' part to the internal capsule. ==Fibres== * The posterior limb of the internal capsule contains [[corticospinal fiber]]s and sensory fibers from the body. * The genu contains [[corticobulbar fiber]]s, which run between the [[cerebral cortex|cortex]] and the [[brainstem]]. * The anterior limb of the internal capsule contains: ** 1) [[frontopontine]] (corticofugal) fibers project from [[frontal cortex]] to [[pons]]; ** 2) [[thalamocortico fibers]] connect the [[Medial dorsal nucleus| medial]] and [[anterior thalamic nuclei|anterior]] nuclei of the thalamus to the [[frontal lobe]]s (these are severed during a [[prefrontal lobotomy]]). * The retrolenticular part contains fibers from the optic system, coming from the [[lateral geniculate nucleus]] of the [[thalamus]]. More posteriorly, this becomes the [[optic radiation]]. Some fibers from the [[medial geniculate nucleus]] (which carry auditory information) also pass in the retrolenticular internal capsule, but most are in the sublenticular part. ==Blood supply== Blood supply is similar to the other structures of the region. mainly [[Striate arteries]], which come off the [[middle cerebral artery]], enter through the [[anterior perforated substance]] in the base of the brain. The capsular branch of [[posterior cerebral artery]] which is called the [[thalamogeniculate artery]] supplies the posterior limb of the capsule, while the anterior limb is supplied by striate arteries from the [[middle cerebral artery]] and Heubner's artery which is the capsular branch of [[anterior cerebral artery]]. ==Pathology== [[Infarction]]s to the internal capsule tend to be small, punctate [[lesion]]s. They can affect sensory and motor systems on the opposite side of the body, and possibly [[eyesight]] (to the contralateral visual field). [[Hearing (sense)|Hearing]] should not be affected in a single capsule lesion, as this information crosses over to both sides of the brain while in the brainstem. ==Additional images== <gallery> Image:Gray684.png|Deep dissection of brain-stem. Lateral view. Image:Gray689.png|Superficial dissection of brain-stem. Ventral view. Image:Gray717.png|Coronal section of brain immediately in front of pons. Image:Gray718.png|Coronal section of brain through intermediate mass of third ventricle. Image:Gray730.png|Section of brain showing upper surface of temporal lobe. Image:Gray743.png|Coronal section through anterior cornua of lateral ventricles. Image:Gray744.png|Coronal section of brain through anterior commissure. Image:Gray745.png|Dissection showing the course of the cerebrospinal fibers. Image:Gray746.png|Diagram of the tracts in the internal capsule. Image:Human brain right dissected lateral view description.JPG|Human brain right dissected lateral view </gallery> ==External links== * {{BrainMaps|internal%20capsule|internal capsule}} * {{BrainInfo|hier|180}} * {{RocheLexicon|13048.000-2}} {{Prosencephalon}} [[Category:Central nervous system pathways]] [[de:Capsula interna]] [[it:Capsula interna]] [[pt:Cápsula interna]]