E, Inferior view of the basal cisterns in the same cerebrum. The medial part of the right parahippocampal gyrus has been removed to expose the temporal horn while preserving the uncus and the fimbria of the fornix. The left posterior cerebral artery and the medial temporal structures have been preserved. The lower lip of the right calcarine sulcus has been removed to expose the cuneus and anterior calcarine veins. The basal vein courses posteriorly around the cerebral peduncle and below the thalamus. The right anterior choroidal artery passes between the lateral geniculate body and the fimbria to reach the choroid plexus in the temporal horn. The left basal vein courses above the posterior cerebral artery. F, The left posterior cerebral artery has been removed to expose the basal vein. The anterior part of the left basal vein is hidden deep to the uncus. The right anterior and posterior longitudinal hippocampal veins course along the fimbria. G, The lower part of the posterior segment of the left uncus plus the parahippocampal gyrus and fimbria have been removed to expose the roof of the left temporal horn. The posterior segment of the left basal vein is missing, because the anterior part drained into a sinus in the tentorial that has been removed instead of draining into the vein of Galen. Uncal veins converge on the basal vein, as does the peduncular vein. The lateral atrial and thalamic veins converge on the calcarine vein. H, Overview. The sylvian veins join the anterior cerebral veins to form the anterior end of the basal vein. The anterior cerebral veins are connected above the optic chiasm by the anterior communicating veins. The anterior segment of the right basal vein is larger than the left. The left atrial veins join the anterior calcarine vein before emptying into the vein of Galen. (Images courtesy of AL Rhoton, Jr.)