406 ANATOMY IN A NUTSHELL. 



mucous membrane of the mouth and Whorton's duct and the submaxillary 

 gland, (b) branches pass from the lingual branch through the submaxillary 

 ganglion with the chorda tympani to the sublingual gland and tongue. Thus 

 we sec that each of these four ganglia has three roots, a motor, a sensory and 

 a sympathetic. 



LESSON CXIV. (Plate CCXIX-CCXX.) 



The superficial origin of the seventh nerve (Plate CLXXXVII) is in the 

 upper part of the groove between the olivary and restiform bodies of the medulla 

 oblongata. The deep origin is in the pons under the floor of the fourth ven- 

 tricle, anterior and external to that of the sixth nerve. The seventh cranial 

 nerve and the eighth cranial nerve were formerly called the seventh and con- 

 sisted of two parts, portio dura, which is now called the seventh, and the 

 portio mollis, which is now called the eighth. The pars intermedia arises 

 from the medulla between the seventh and eighth cranial nerves and is connected 

 with them at its origin. The seventh nerve or facial nerve is the motor nerve 

 of the facial muscles of expression, of the muscles of the external ear, Platysma 

 myoides, Buccinator, posterior belly of the Digastric, Stylo-hyoid, Lingualis, 

 and Stapedius. This nerve passes with the eighth nerve into the internal aud- 

 itory meatus where they are joined by the pars intermedia. From the internal 

 auditory meatus it runs into the aqueductus Fallopii where it has an enlarge- 

 ment upon it called the geniculate ganglion, which is reddish in color. It now 

 bends backward on the inner wall over the fenestra ovalis and then runs ver- 

 tically downward behind the tympanum to the stylo-mastoid foramen. After it 

 passes out of the stylo-mastoid foramen it runs forward in the parotid gland and 

 crosses the external carotid artery. At the ramus of the jaw it divides into the 

 temporo-facial and cervico-facial branches. These two branches with their 

 sub-divisions form the pes anserinus. 



The seventh nerve gives off the following branches of communication, (1) 

 in wditory canal, (a) small branches to the auditory nerve, (2) in aqueduct 

 of Fallopius, (a) large superficial petrosalfrom thegeniculate ganglion which 

 with the large deep petrosal forms the vidian nerve. This nerve passes to 

 Meckel's ganglion, (b) Small superficial petrosal passes from the geniculate 

 ganglion to the otic ganglion, (c) external superficial petrosal from the genicu- 

 late ganglion to the sympathetic plexus around the middle meningeal artery, 

 (d) a branch to the auricular branch of the pneumogastric (Arnold's). (3) At 

 tin. exit OF the stylo-mastoid foramen (a) a branch to the great auricular 

 of the cervical plexus, (b) to auriculo-temporal of the fifth, (c) a branch to the 

 pneumogastric, (d) a branch to the glosso-pharyngeal. (4) Behind the ear, 

 a branch of communication to the small occipital. (5) On the face, 

 branches to the three divisions of the fifth nerve. (6) In the neck, branches 

 to the superficial cervical. 



The seventh nerve has the following branches of distribution 



(1) I.\ the aqueduct of Fallopius, (a) tympanic branch which arises 

 opposite the pyramid and passes through a small canal in the pyramid to the 



