A large venous sinus along the attached border of the falx cerebri from the crista galli to the internal occipital protuberance, where it joins either the right or left transverse sinuses or both. At its caudal end (at the back of the tentorium cerebelli), the superior sagittal sinus joins the straight sinus to form the confluence of the sinuses, from which the right and left transverse sinuses carry the accumulated venous blood toward the internal jugular veins.