386 



LABORATORY MANUAL OF HUMAN ANATOMY 



tegmentalis). Note that the epitympanic recess (recessus epi- 

 tympanicus} is opened into; observe its cupolar portion (pars 

 cupularis). The general shape of the cavity and walls of the 

 tympanum may easily be remembered by thinking of a miniature 

 cigar-box obliquely placed inside the temporal bone. Study the 

 following : 



(a) Jugular wall (paries jugularis) (0. T. floor). 



(ab) Styloid prominence (prominentia styloidea). 



(b) Mastoid wall (paries mastoidea) (0. T. posterior wall). 



(ba) Tympanic antrum (antrum tympanicum) (0. T. mastoidal 



antrum). 



(bb) Prominence of lateral semicircular canal (prominentia canalis 



semicircularis lateralis). 

 (be) Prominence of facial canal (prominentia canalis facialis). 



(bd) Pyramidal eminence (eminentia pyramidalis). 



(be) Fossa of incus (fossa incudis). 



(bf) Posterior sinus (sinus posterior). 



(bg) Tympanic aperture of canaliculus of chorda (apertura tym- 



panica canaliculi chordae). 



(c) Carotid wall (paries carotica) (0. T. anterior wall). 



FIG. 187. 



Prominentia canalis semicircularis lateralis 



Eminentia pyramidalis, 

 Fenestra vestibuli i 

 Processus cochleariformis 



Semicanalis M. tensoris tympani ' 



Semicanalis tubae auditivae \ 



Antrum tympanicum 



Canal for the M. stapedius 



Canalis 

 caroticw 



.Margo occipitalis 



Canalis facialis 

 (FaUoppii) 



^Cellulae mas- 

 toideae 



Sulcus promontorii ; \ 

 Cavum tympani / 



Promontorium i 

 Fossula fenestrae cochlea^ 



Incisura mastoidea 



The medial wall, paries labyrinthicus, of the left bony tympanic cavity, and the mastoid cells, 

 cettulae mastoideae, shown in a section through the mastoid process and the anterior part of the petrous 

 part of the temporal bone. Seen from the anterior and lateral side. (After Toldt, Anat. Atlas, Wien, 

 1903, 3 Aufl., p. 927, Fig. 1432.) 



(d) Labyrinthic wall (paries labyrinthicus) (0. T. inner wall). (Fig. 

 187.) 



(da) Fenestra ("window") of vestibule (fenestra vestibuli) (0. T. 



fenestra ovalis). 



(daa) Fossula of fenestra of vestibule (fossula fenestrae 

 vestibuli). 



(db) Promontory (promontorium) . 



