560 



DISSECTION OF THE FACE. 



irregular in 

 shape ; 



relations ; 



accessory 

 part. 



The duct 

 reaches 

 mouth : 



surface 

 marking, 



its length 

 and size. 



Surface of 

 gland. 



Dissection 

 to see deep 

 parts. 



Deep part- 

 sinks behind 

 jaw. 



Vessels and 



and is named from its position. its excretory duct enters the 

 mouth through the middle of the cheek. 



The shape of the gland is irregular, and is determined by the 

 surrounding parts. Thus below, where there is not any resisting 

 structure, the parotid projects into the neck, and comes into close 

 proximity with the submaxillary gland, though separated from it by 

 a process of the cervical fascia ; a horizontal line from the angle of 

 the jaw to the sterno-mastoid muscle usually marks the extent of 

 the gland in this direction. Superiorly, the parotid is limited by the 

 zygomatic arch and the temporal bone. Along the posterior part 

 the sterno-mastoid muscle extends ; but anteriorly, the gland projects 

 somewhat into the face over the masseter muscle, and has connected 

 with it in this situation a small accessory part, known as the soda 

 parotidis. 



Issuing from the anterior border is the excretory duct duct of 

 Stenson (fig. 204), which crosses the masseter below the socia 

 parotidis, and perforates the buccinator and the mucous mem- 

 brane of the cheek obliquely opposite the second molar tooth of 

 the upper jaw. The duct lies between the transverse facial 

 artery and some branches of the facial nerve, the latter being 

 below it. A line drawn from the meatus auditorius to a little 

 below the nostril would mark the level of the duct on the face ; 

 and the central point of the line would be opposite the opening 

 into the mouth. The length of the duct is about two inches and 

 a half ; and its capacity is large enough to allow a small probe to 

 pass, but the opening into the mouth is much less. 



The cutaneous surface of the parotid is smooth, and three or four 

 lymphatic glands are seated on it : but from the deep part processes 

 are sent into the inequalities of the space between the jaw and the 

 mastoid process. 



Dissection. By removing the parotid gland, cautiously and piece- 

 meal, from behind and below, the hollows that it fills will come 

 into view : at the same time the dissector will see the vessels and 

 nerves that pass through it. An examination of the processes of 

 the gland, and of the number of important vessels and nerves in 

 relation with it, will demonstrate the dangers attending any opera- 

 tion on it. The duct may be opened, and a pin may be passed 

 along it to the mouth, to show the position and the diminished size 

 of the aperture. 



Two large processes of the gland extend deeply into the neck. 

 One dips behind the styloid process, and projects beneath the 

 mastoid process and sterno-mastoid muscle, where it reaches the 

 deep vessels and nerves of the neck. The other piece is situate in 

 front of the styloid process ; it passes into the glenoid hollow behind 

 the articulation of the lower jaw, and sinks beneath the ramus of 

 that bone along the internal maxillary artery. 



Coursing through the middle of the gland is the external carotid 

 artery, which ascends behind the ramus of the jaw, and furnishes 

 the posterior auricular, superficial temporal, and internal maxillary 

 branches. Superficially to the artery lies the trunk formed by the 



