The inferior petrosal sinuses, within the human head, are beneath the brain and allow blood to drain from the center of the head.
They drain on either side inferiorly from the cavernous sinus (beneath the brain) and join with the sigmoid sinus to form the internal jugular vein, which continues inferiorly to drain blood from the base of the skull.
The inferior petrosal sinus is situated in the inferior petrosal sulcus, formed by the junction of the petrous part of the temporal bone with the basilar part of the occipital bone.
It begins in the postero-inferior part of the cavernous sinus and, passing through the anterior part of the jugular foramen, ends in the superior bulb of the internal jugular vein.
The inferior petrosal sinus receives the internal auditory veins and also veins from the medulla oblongata, pons, and under surface of the cerebellum.