SENSE ORGANS AND COMMON INTEGUMENT 



93 



Spiral canal of cochlea 

 Modiolus (" screw ") 

 Base of modiolus 

 Shelf of modiolus 

 Osseous spiral shelf 

 Hooklet of spiral shelf 

 " Staircase" of vestibule 

 " Staircase" of tympanum 

 Helicotrema (" pore of the helix ") 

 Secondary spiral shelf 

 Spiral canal of modiolus 

 Longitudinal canals of modiolus 



Internal acoustic meatus 



Internal acoustic opening 



Bottom of internal acoustic meatus 



Transverse crest 



Area of facial nerve 



Area of cochlea 



Foraminous spiral tract 



Superior vestibular area 



Inferior vestibular area 



Isolated foramen 



Cavity of tympanum 



Tegmental wall 

 Epitympanic recess 

 Cupular portion 

 Jugular wall (O. T. floor) 



Styloid prominence 



Labyrinthic wall (O. T. in- 

 ner wall) 

 Fenestra ("window") of vestibule 



(O. T. fenestra ovalis) 

 Little fossa of fenestra of vestibule 

 Promontory 

 Sulcus of promontory 

 Subiculum (" support ") of promon- 

 tory 



Sinus of tympanum 

 Fenestra of cochlea (O. T. fenestra 



rotunda) 

 Little fossa of fenestra of cochlea 



Crest of fenestra of cochlea 



Cochleariform process 

 Mastoid wall (O. T. pos- 

 terior wall) 



Tympanic antrum (O. T. mastoidal 

 antrum) 



Prominence of lateral semicircular 

 canal 



Prominence of facial canal 



Pyramidal eminence 



Fossa of incus 



Posterior sinus 



Tympanic aperture of canaliculus of 



chorda 

 Mastoid cells 

 Tympanic cells 



Carotid wall (O. T. ante- 

 rior wa 1 1 ) 

 Membranous wall (O. T. 



outer wall) 



Membrane of the tympanum (0. T. 

 drumhead) 



Flaccid part 



Tense part 



Border of membrane of tympanum 



Anterior malleolar fold 



Posterior malleolar fold 



Malleolar prominence 



Malleolar stripe 



Umbo ("prominent part") of tympanic 



membrane 

 Cutaneous layer 

 Fibrocartilaginous ring 

 Radiate layer 

 Circular layer 

 Mucous layer 



Auditory ossicles 



Stirrup 

 Head of stirrup 

 Anterior limb 

 Posterior limb 



