The internal capsule is an anatomical structure in the brain, containing ascending and descending tracts.
Location: The internal capsule is best viewed in a horizontal section of the brain, through the basal ganglia. It is composed of three sections: the anterior limb, genu, and the posterior limb. The anterior limb is lateral to the head of the caudate nucleus and medial to the lenticular nucleus. The genu abuts the third ventricle medially, and the globus pallidus forms its lateral border. The posterior limb is lateral to the thalamus and medial to the lenticular nucleus.
Vascular supply: The anterior limb of the internal capsule is supplied by the recurrent artery of Heubner off of the anterior cerebral artery and lenticulostriate branches off of the middle cerebral artery. The posterior limb is supplied by lenticulostriate branches off of the middle cerebral artery and the anterior choroidal artery off of the internal carotid artery.