714 



THE EAE 



THE VASCULAR SUPPLY 



Blood Supply. The internal ear is supplied by the internal audi- 

 tory artery, a branch of the basilar artery, which enters the labyrinth 

 along with the acoustic nerve, and at once divides into two main stems, 

 the vestibular and the cochlear (arteria cochlearis communis, Sieben- 



d f 



FIG. 590. SCHEME OF THE VASCULAR SUPPLY OF THE INTERNAL EAR. 



C 1 , first turn of the cochlea; S, saccule; Sup.S.C., Ext.S.C., and PosLS.C., superior, 

 external, and posterior semicircular canals; U, utricle. The arteries are in heavy 

 black, the veins somewhat lighter; a, central vein, and 6, central artery of the cochlea; 

 c, vestibular artery; d, vestibulocochlear artery; e, arteria proprise cochleae; /, vena 

 aqueductus cochleae; g, vena aqueductus vestibuli. 



mann) . The vestibular artery accompanies the branches of the vestibular 

 nerve to the saccule, utricle, and semicircular canals, supplying these 

 structures in the posterior portion of the vestibule, and forming a rich 

 plexus in the connective tissue of the maculae and cristse, and a more 

 scanty network in the remaining portions of the membranous labyrinth. 

 The cochlear division of the internal auditory artery, according to 

 Siebenmann, promptly subdivides into the cochlear artery proper, which 

 appears as the continuation of the vessel, and the vestibulocochlear 



