The petrosal sinuses (Latin: sinus petrosus superior, sinus petrosus inferior) are two paired dural venous sinuses located on the petrous part of the temporal bone on each side. There is a superior and an inferior petrosal sinus.
The superior petrosal sinus arises from the sinus cavernosus, then it runs posterolaterally in the attached margin of the tentorium cerebelli. Further, it passes in a groove on the superior border of the petrous part of the temporal bone called the superior petrosal sulcus. Finally, it drains into the transverse sinus. The superior petrosal sinus receives venous blood from the superior petrosal vein, and, occasionally, from the inferior cerebral and tympanic veins.
The inferior petrosal sinus arises from the cavernous sinus, passes posteriorly in the petroclival fissure. Further, it runs through the jugular foramen and drains into the superior jugular bulb. The inferior petrosal sinus receives venous blood from the labyrinthine veins, and small veins from the medulla oblongata, pons, as well as the inferior cerebellar surface.