Dissection of Sheep^s Head, 237* 



Maxillary, we may, by careful investigation of the intervening 

 area, arrive at the Eustachian tube, and Internal Pterygoid nerve. 

 Just at the point where the Auriculo- temporal nerve runs in 

 to the main trunk, but internal and posterior to it, will be 

 found the short branch of the Internal Pterygoid nerve 

 leaving the Inferior Maxillary to penetrate the Internal 

 Pterygoid muscle; when this is cleaned there will be seen 

 underlying it, at a slight angle, a small strip of muscle ; and 

 between this strip of muscle and the Inferior Maxillary root 

 a bluish hard tube will be readily distinguishable, which is 

 the proximal end of the Eustachian tube, i.e., the canal which 

 leads from the cavity of the tympanum to the upper part of 

 the Pharynx. 



The Eustachian tube and Internal Pterygoid nerve thus 

 found, give us the bearings of the anterior portion of the 

 diffused Otic ganglion. This ganglion is of a reddish-grey 

 colour, and situated on the deep surface of the Inferior 

 Maxillary trunk, around the origin of the Internal Pterygoid 

 branch. Its inner surface is close to the cartilaginous part 

 of the Eustachian tube. It is perhaps best seen by pressing 

 back the united Gustatory and Inferior Dental branches : 

 the ganglion occupying the apex of a triangle of which these 

 nerves form the left side, the Buccal nerve the right side, 

 and the Internal Maxillary artery the base. 



The Facial branch of the seventh nerve may be now cleaned up 

 to the sJmll, i.e. to the Stylo-mastoid foramen, situated between 

 the Paroccipital process, the external auditory meatus, and the 

 commencement of the Stylo-hyoid chain of bones and liga- 

 ments. 



The large compressed Stylo- hyal bone may be now cleaned 

 at its proximal end, and the prominent posterior process 

 exposed : the normal anterior boundary being traced up 

 internal to the Parotid gland and Carotid artery (which 

 should both be slightly turned over to the front) to its short 



