A, The basal surface of the frontal lobe is drained by the frontopolar, anterior and posterior fronto-orbital veins, and the olfactory veins. The anterior fronto-orbital veins empty into the anterior part of the superior sagittal sinus or its tributaries. The posterior fronto-orbital veins empty into the veins below the anterior perforated substance that converge on the anterior end of the basal vein. B, Enlarged view. The optic chiasm has been reflected downward to expose the anterior cerebral veins passing above the optic chiasm and being joined by the paraterminal veins that course along the medial surface of the hemisphere below the genu of the corpus callosum. The olfactory, paraterminal, anterior cerebral, and posterior fronto-orbital veins converge on the anterior end of the basal vein. C, Basal surface of the temporal lobe. The anterior part of the basal surface of the temporal lobe is drained by the temporosylvian veins that empty into the veins along the sylvian fissure. The right temporobasal veins empty into a tentorial sinus located just medial to the transverse sinus. The area normally drained by the left anterior and middle temporobasal veins is drained predominantly by a long trunk that passes along the long axis of the basal surface and empties at a tentorial sinus. The yellow and red arrows are on the terminal end of veins that empty into the right and left tentorial sinuses shown in D. D, Superior view of the tentorial sinuses into which the temporobasal veins shown in C empty. The long vein on the left basal surface empties into the tributary of the left tentorial sinus shown by the red arrow. The temporobasal veins on the right side empty into the right tentorial sinus with multiple tributaries. The vein shown with the yellow arrow in C empties into the tributary of right tentorial sinus shown with a yellow arrow in D. (Images courtesy of AL Rhoton, Jr.)