A, Superior view. The central core is the part of the cerebrum located between the insula and the third and lateral ventricles. The upper part of the left hemisphere, except the precentral gyrus, has been removed to expose the frontal horn and body of the ventricle. The precentral gyrus is located lateral to the posterior part of the body of the ventricle and lateral to the splenium of the corpus callosum. The postcentral gyrus, which has been removed, faces the most anterior of the transverse temporal gyri, called Heschl’s gyrus. The short insular gyri are exposed anterior to and the long gyri behind the precentral gyrus. B, Axial section extending through the central core crosses the anterior and posterior limb and genu of the internal capsule, the thalamus, and the lentiform and caudate nuclei at the level of the foramen of Monro. The lateral wall of the atrium and the roof of the temporal horn have been removed by dividing the white matter along the circular sulcus of the insula. C, The posterior part of the lateral surface of the insula has been removed to expose the lateral surface of the lentiform nucleus. The choroid plexus is attached along the choroidal fissure that extends from the foramen of Monro to the inferior choroidal point located just behind the head of the hippocampus. D, The anterior part of the insular cortex has been removed to expose the lentiform nucleus in the area above and behind the sylvian fissure, and above the anterior perforated substance and temporal horn. The middle cerebral artery, in the stem of the sylvian fissure, passes below the anterior part of the caudate and lentiform nuclei. The sublenticular and retrolenticular parts of the internal capsule, including the optic and auditory radiations, pass below and behind the lentiform nucleus. The anterior limb of the internal capsule is located between the caudate and lentiform nuclei, and the posterior limb is positioned between the lentiform nucleus and thalamus. E, Enlarged view of the lower margin of the thalamus and upper part of the uncus. The anterior segment of the uncus contains the amygdala and faces the carotid and middle cerebral arteries. The posterior segment of the uncus contains the head of the hippocampus and is located anterior to the lower end of the choroidal fissure. The lateral geniculate body is located just above the choroidal fissure and body of the hippocampus. The choroidal fissure, along which the choroid plexus is attached, is located between the fimbria and the thalamus. The inferior choroidal point, the lower end of the choroidal fissure, is located behind the hippocampal head. F, The thalamus has been removed and the fimbria of the fornix retracted laterally to expose the parahippocampal gyrus medial to the fimbria. The posterior cerebral artery courses through the crural and ambient cisterns on the medial side of the parahippocampal gyrus. The upper lip of the calcarine sulcus, formed by the cuneus, has been removed to expose the lower lip formed by the lingula. The deep end of the calcarine sulcus forms a prominence, the calcar avis, in the medial wall of the atrium. (Images courtesy of AL Rhoton, Jr.)