ANATOMY IN A NUTSHELL. 579 



Lymphatics of the internal ear end in the tympanic and intracranial 

 lymphatic vessels. 



The superficial mesial origin of the auditory nerve is from the groove be- 

 tween the olivary and restiform bodies at the lower border of the pons. 



The deep mesial origin is in the dorsal auditory nucleus, which is on the 

 outer side of the inferior fovea on the floor of the fourth ventricle 



The superficial lateral origin of the auditory nerve is from the auditory 

 striae, and after winding around the upper end of the restiform body joins the 

 mesial root in the groove between the olivary and restiform bodies. 



The deep lateral origin is from (1) a ganglion of the lateral root, which is 

 situated in this root as it winds around the restiform body, (2) the auditory 

 striae, (3) the trapezium of the pons, (4) the ventral auditory nucleus. This 

 last nucleus lies in front of the restiform body between the two roots. 



The main trunk of the auditory nerve now passes into the internal auditory 

 meatus with the facial nerve and the auditory artery. At the bottom of this 

 meatus it comes to the lamina cribrosa, where it divides into the cochlear branch 

 and the vestibular branch. (Plate CCXXI). 



The cochlear branch sends branches to the saccule, to the ampulla of the 

 posterior semicircular canal, and to the hair cells of the organ of Corti in the 

 membranous cochlea. 



The vestibular branch has upon it the ganglion of Scarpa,while in the internal 

 auditory meatus it sends branches to the utricle, to the ampulla of the external 

 semicircular canal, to the ampulla of the posterior semicircular canal. 



The principal salivary glands are the parotid, submaxillary, and 

 sublingual. 



The parotid gland takes its name from its position which is near the ear. 

 It is about the size of the pinna (auricle) of the external ear, and weighs almost 

 an ounce. It extends from the mastoid process and the angle of the jaw BE- 

 LOW to the zygoma above, being immediately in front of the external meatus. 

 This gland is saddled over the ramus of the lower jaw, and lias upon its outer 

 surface a few lymphatic nodes, while its inner surface has two processes upon 

 it. One of which extends behind the styloid process of the temporal bone and 

 beneath the mastoid process of the same bone, while the other is in front of the 

 styloid process. The following structures pass through the parotid gland: (1) 

 the external carotid artery which gives off the temporal branch above, the 

 posterior auricular behind, and the internal maxillary internally, also the trans- 

 verse facial artery which is a Iranch of the temporal passes through the upper 

 part of the "land, (2) the common trunk formed by the temporal and internal 

 maxillary veins, (3) a branch connecting this trunk with the internal jugular 

 rein, (4) the facial nerve and its branches. (.">) branches of the greal auricular 

 nerve. 



The upper anterior portion of the gland is called socia parotidis. This 

 portion is often detached from the rest of the gland. 



The duct of this gland is about two and one-half inches long. It is called 

 Stenson's or Steno's duct. After crossing the Masseter muscle and passing 



into tin 1 substance of the Buccinator muscle this duct opens upon the inner sur- 



