Coronal section of the right hemisphere at the level of the lenticular nucleus and hypothalamus. The central core of the cerebral hemisphere is a well-deliniated block of tissue located between the cerebral lobes and the brainstem.   It is comprised at the level shown here, from lateral-to-medial, of: 1) the insular cortex, 2) the extreme capsule (composed of insular and opercular association fibers), 3) the claustrum, a thin strip of gray matter that is widely interconnected to hemispheric structures, 4) the external capsule (formed by the uncinate fasciculus and inferior orbitofrontal fasciculus anteriorly; and claustrofugal fibers posteriorly), 5) the lentiform nucleus, comprised from lateral-to-medial of the putamen, lateral medullary lamina, globus pallidus externa, medial medullary lamina, and globus pallidus interna, 6) the internal capsule (which joins the external capsule superior to the putamen to form the corona radiata, and 7) the head of the caudate nucleus, which forms the ventrolateral wall of the anterior horn of the lateral ventricle. (Image courtesy of AL Rhoton, Jr.)