sagittal sinus [L, sagitta, arrow, sinus, hollow] , either of two venous sinuses of the dura mater. The superior venous sinus begins near the crista galli and drains backward to empty into a confluence of sinuses near the occipital area. The inferior venous sinus begins in the lower margin of the cerebral falx and follows the superior venous sinus, emptying into the straight sinus.
