328 



NERVE OF EXPRESSION. 



FIG. &7. 



expression and motion to the face, and is one of the respi- 

 ratory nerves of Sir Charles Bell. It arises from what is 

 termed by this latter gentleman, the respiratory tract, and 



from that particular por- 

 tion of this tract, lying 

 between the corpus olivare 

 and corpus restiforme, at 

 the upper part of the 

 medulla oblongata, and 

 near the pons, whence its 

 fibres are traced into the 

 corpus restiforme. It is 

 smaller than the auditory 

 nerve, and anterior and 

 superior to it in the mea- 

 tus auditorius internus, 

 where they both enter, 

 and where they inter- 

 change connecting filaments. After the facial nerve tra- 

 verses the auditory meatus, at the bottom of this latter, it 

 enters the aqueduct of Fallopius pursues the course of this 

 canal, which is between the cochlea and vestibule, and 

 behind the tympanum proceeds, first, horizontally back- 

 ward, then outward above the fenestra ovalis, and de- 

 scends along the inner wall of the tympanum, to the stylo 

 mastoid foramen, at which it emerges. From this point it 

 proceeds forward in the substance of the parotid gland, 

 crossing the external carotid artery, and external jugular 

 vein, to the ramus of the lower jaw, behind which it 

 divides into two branches called the temporo-facial, and 

 cervico-facial. Opposite to the hiatus Fallopii, the Vidian 



FIG. 97 represents the Facial nerve, or Portio-dura of the seventh pair, a 

 Trunk of the facial nerve, 6 Ascending branch, c Descending branch, d 

 Posterior auricular branch, e e Temporal branches. // Malar branches- 

 g g Inferior maxillary branches, h Occipital nerve, i Terminal branches of 

 the inferior dental, j Terminal branches of infra orbital, k k Supra orbital 

 nerve and branches. I Orbicularis oris muscle, in Zygomaticus major, n 

 Zygomaticus minor, o Levator labii superioris alceque nasi. p Orbicularis 

 palpebrarum. q Depressor anguli oris. 



