39 



HISTOLOGY. 



and the upper lateral portion of the sacculus, utriculus and semicircular 

 ducts. The cochlear artery sends a vestibulo-cochlear branch to the lower 

 and medial portion of the sacculus, utriculus, and ducts. This branch 

 also supplies the first third of the first turn of the cochlea. The capillaries 

 formed by the vestibular branches are generally wide meshed, but near the 

 maculae and cristae the meshes are narrower. The terminal portion of 



laris 



Ductus semicircu 

 superior. 



Ampulla lateralis. 



quaeductus 

 itibuli. 



semicircularis 

 lis. 



Arteria. 

 cochlearis. 



Vestibulo-cochlear 



branch of the 

 arteria cochlearis. 



uctus semicircular! 

 posterior. 



Vena spinalis. 



Vena vestibularis 



Vena aquaeductus cochleae. 



FIG. 439. DIAGRAM OF THE BLOOD VESSELS OF THE RIGHT HUMAN LABYRINTH. MEDIAL AND POS- 

 TERIOR ASPECT. 



D. c., Ductus cochlearis; S., sacculus; U., utriculus; i, ductus reuniens;', 2, ductus utriculo-saccu laris. 

 The saccus endolymphaticus is cut off. 



the cochlear artery enters the modiolus and forms three or four spirally 

 ascending branches. These give rise to about thirty radial branches 

 distributed to three sets of capillaries (Fig. 440); i, those to the spiral 

 ganglion; 2, those to the lamina spiralis; and 3, those to the outer walls 

 of the scalae and the stria vascularis of the cochlear duct. 



The -veins of the labyrinth form three groups, i. The vena aquae- 



