444 



Veins of the Head. 



Emissariuni 

 parietale 



v. diploica temporalis anterior 



V. diploica 

 frontalis 



V. diploica 

 occipitalis 



I 



Emissarium 

 occipitale 



V. diploica temporalis i Emissarium 

 posterior mastoideum 



485. Venae diploicae, viewed from the right. 

 (The lamina externa of the roof of the skull has been filed off.) 



10. Sinus petrosHS inferior (inferior petrosal sinus) (see Figs. 483 and -484), paired, 

 extends lateralward and downward on each side from the posterior, inferior portion of the sinus 

 caveniosus in the sulcus petrosus inferior of the occipital and temporal bones to the foramen 

 jugulare and runs downward through its most anterior subdivision; it opens, either in the 

 foramen jugulare ov l)elow it, into the bulbus v. jugularis superior. 



li. Plexus basilaris (see Figs. 483 and 484), unpaired, lies as a plexus upon the 

 clivus and is connected above, on both sides, with the sinus cavernosus and the sinus petrosus 

 inferior, below, at the foramen occipitale magnuui, witli the plexus venosi vertebrales interni. 



Yv. cerebri collect the blood partly from the surface, partly irom the ijiterior of the 

 brain and open into sinus durae matris (see Neurology); they possess no valves. 



Vv. nieningeae (see Figs. 483 and 484), stand open, are devoid of valves, are numerous 

 in the dura mater encephali, are connecttxl above with the sinus sagittalis superior and anasto- 

 mose manifoldly with one another. They accompany the stems of the corresponding arteries, 

 there being usually two veins to one artery, and open into a neighboring sinus. The vv. 

 mcningeae mediae, usually two in number, run near t\w a. meningea media, are connected with 

 the sinus splienoparietalis and the reto foramiuis ovalis, extend downward through the foramen 

 spinosum and open into the plexus pterygoideus. 



Vv. auditivae intcrnae (not illustrated) come fi-om the internal ear through the meatus 

 acusticus internus and open into the sinus transversus or the sinus petrosus inferior. 



