232 



Organ of Hearing. 



Alamibrium 

 'mallei 



316. The Membrana tympani and Eustachian Tube 



from the inner side. After a specimen of A. P o 1 i t z e r. 



The E u s t a c h i a n tube, Tuba Eustacliii, commences at the anterior 

 wall of the tympanic cavity, below the Semicanalis tensoris tympani with 

 the Ostitim tympanicum, runs obliquely forwards, inwards and downwards, 

 and terminates at the side of the pharynx, with the Ostium pliaryngeum. 

 The tube consists of an osseous and a cartilaginous portion. 



The small bones of the ear, Ossicula amlitus, are three in 

 number : 



The Malleus, or h a m m e r b o n e, is divided into a h e a d, neck, 

 handle, short and long process. The handle or Manubrium 

 is connected with the Membrana tympanl ; the short process, Processus 

 brcvis, is situated at the root of the handle and projects outwards toward 

 the Membrana tympani; the long process, Processus Folii seu gracilis 

 lies in the Fissura Glaseri. 



