436 



ANATOISIY FOR NURSES 



[Chap. XX 



Internal ear 



Ear 



Vestibule — antechamber 

 just inside of fenestra 

 oralis . 



Semicir- 

 cular 

 canals 



Cochlea 



Auditory 

 nerve 



Three in num- 

 ber. 



Open into ves- 

 tibule. 

 Vestibular branch of audi- 

 Bony tory nerve tlistributed to 



labyrinth I vestibule and semicircu- 

 lar canals. 



A spiral tube. 

 2^ turns around 



modiolus. 

 Fenestra ro- 

 tunda. 

 Cochlear branch 

 of the audi- 

 tory nerve. 

 ' Surrounded by perilymph. 

 Contains endoljTiiph. 

 Lines the vesti- f Saccule, 

 bule \ Utricule. 



Lines the semicircular 



canals. 

 Lines the cochlea, and here 

 Membranous i it is called the canalis 

 labyrinth cochlearis, or scala media. 



Menibrana basilaris is name 

 given to membrane at 

 base of canal. 

 Organ of Corti, name given 

 to end organs of auditory 

 nerve lodged on mem- 

 brana basilaris. 

 Cochlear — terminates in and around cells 



of organ of Corti. 

 Vestibular — terminate in hair-cells of 

 saccule, utricle, and ampulla. 



