Midsagittal perspective of the head. The superior sagittal sinus lies within the superior border of the falx cerebri while the inferior sagittal sinus lies within its inferior border. The straight sinus is formed by the union of the inferior sagittal sinus and great cerebral vein (of Galen) and is located at the intersection of the falx celebri and tentorium cerebelli. The occipital sinus is located in the falx cerebelli.  The superior sagittal, straight, and occipital sinuses converge at the torcular Herophili (confluens of sinuses). The basilar artery can be viewed near the ventral surface of the pons, between it and the clivus, and the anterior cerebral artery can be seen arching over the corpus callosum. It gives rise to the pericallosal artery, which in turn gives rise to the callosomarginal artery.  (Image courtesy of AL Rhoton, Jr.)