Bones of the Cranium. 



17 



Annulus 

 tympanicus 



17. Left Temporal Bone 18. Left Temporal Bone 

 at birth, at birth, 



from the outside. from the inner side. 



In the first year of life the temporal bone consists of three pieces : 

 a) Squamoiis portion, Pars squamosa, b) Auditory process or Annulus tym- 

 panicus, and c) Petroso-mastoid portion, Pars petroso-mastoidea. The Pars 

 petroso-mastoidea is separated from the Pars squamosa by the Sutura petroso- 

 squamosa and the Fissura mastoideo-squamosa (J o s. G r u b e r). The Annulus 

 tympanicus contains the Membrana tympani ; in the tympanic cavity, Cavum 

 tympani (behind the Membrana tympani) the Foramen ovale and Foramen 

 rotundum can be seen. 



The temporal bone articulates with 5 bones: with the occipital, the 

 parietal, the sphenoid, the malar and the inferior maxillary bones. 



llcitzmann, Atlas. I. 



