Inferior petrosal sinus
The inferior petrosal sinus is one of the dural venous sinuses. It is often a plexus of venous channels rather than a true sinus and drains blood from the cavernous sinus to the jugular foramen (pars nervosa) or sometimes via a vein which passes through the hypoglossal canal to the suboccipital venous pelxus.
It runs in a shallow groove between the petrous temporal bone and basilar occipital bone (on either side of the clivus). It is connected across the midline by the basilar plexus.
Along with the cavernous sinus, is receives tributaries from the medulla oblongata, pons and inferior surface of the cerebellum as well as labyrinthine veins (via the cochlear canaliculus and the vestibular aqueduct)
