THE VEINS OF THE HEAD AND NECK 



289 



to end in the lateral sinus at the fossa sigmoidea. It receives 

 the inferior cerebral, superior cerebellar, and some tympanic 



veins. 



9. The inferior petrosal, in the groove between the basilar 

 process and petrous portion, runs from the cavernous to join 

 the lateral sinus at the jugular foramen, completing the internal 

 jugular vein. (See under Internal Jugular Vein.) It receives 

 the auditory and some inferior cerebellar veins. 



Dura mater linin 

 pituitary fossa. 



FIG. 48 

 'Lining membrane of sinus. 



"Third nerve. 



Sixth nerve.* 

 Internal carotid. 



Fourth nerve. 



First division of fifth nerve. 



Showing the relative position of the structures in the right cavernous sinus, 



viewed from behind. 



10. The transverse (basilar) sinus is a plexus in the dura mater 

 over the basilar process. It joins the anterior spinal veins below 

 and the two inferior petrosal sinuses laterally. 



The ophthalmic veins are superior and inferior. 



The superior passes back from the root of the nose with 

 the ophthalmic artery through the sphenoidal fissure to the 

 cavernous sinus. 



The inferior runs back, near the floor of the orbit, to open into 

 the cavernous sinus, sometimes joining the superior. 



The diploic veins run between the tables of the skull and open 

 into the dural sinuses or externally. 



The emissary veins are small veins connecting the cranial 

 sinuses with the veins outside by means of foramina in the bones. 

 These are the principal: one each 



(a) Through the mastoid foramen, from the lateral sinus to 

 the outermost occipital vein. 



(b) Through the posterior condylar foramen, from the lateral 

 sinus to the cervical venous plexus. 



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