42 TOPOGRAPHICAL ANATOMY OF THE 



The parotid gland (Glandula parotis). — The parotid ^ gland is the 

 largest of the salivary glands and occupies the depression below the ear 

 and between the wing of the atlas and the border of the ramus of the 

 mandible. Its ventral end reaches the external maxillary vein. 



In outline the gland is irregularly four-sided. The middle of its 

 length is the narrowest part ; the upper and lower ends being somewhat 

 broader, and, not infrequently, the upper end is the broadest part. 



Like the other salivary glands, the parotid is composed of lobules 

 held together by somewhat loose fibrous tissue. Close inspection shows 

 that the larger, primary lobules consist of collections of smaller, 

 secondary lobules. 



The lateral surface of the gland is covered by the inferior auricular 

 and cutaneous muscles ; and lying upon its lower part are the internal 

 maxillary vein and the ramus colli of the facial nerve, which commonly 

 pierce the gland together about its middle. The posterior auricular 

 vein frequently lies on this surface just below the ear. 



The anterior border is tbin and irregular, overlaps the masseter 

 muscle to a greater or less extent, and is related to the transverse facial 

 vessels, the superficial temporal nerve, the common trunk of the buccal 

 nerves, and the masseteric vessels. The posterior border is loosely 

 connected with the adjacent muscles, and is slightly concave to fit the 

 border of the wing of the atlas. Running along part of it is the 

 auricular branch of the second cervical nerve. 



The lower (ventral) end of the gland is in contact with the external 

 maxillary vein, and that branch of the nervus cutaneus colli that 

 accompanies this vessel into the space bounded by the mandible. The 

 upper (dorsal) end is very thin and irregular, and embraces the base of 

 the concha of the ear, spreading for a variable distance underneath the 

 anterior auricular muscles. 



The deep surface of the parotid has a large number of relations, 

 among which are the facial nerve and a number of its branches, the 

 external carotid artery, the digastric and jugulo-mandibular muscles, 

 the tendon of insertion of the sterno-cephalic muscle and an aponeurotic 

 sheet joining it to the brachio-cephalic tendon and separating the parotid 

 and submaxillary glands. 



The parotid duct (ductus parotideus) results from the union, about 

 the anterior ventral angle of the gland, of a number of smaller ducts 

 that may be readily discovered at the anterior border. The duct 

 crosses the tendon of insertion of the sterno-ceijhalic muscle, and, pass- 

 ing medial to the jugulo-mandibular and pterygoid muscles, gains the 

 mandibular space, where it has already been examined (pages 12 and 39). 

 1 TTopd (para) [Gr.], about -f- ous (ous) [Gr.], the ear. 



