PAROTID GLAND 263 



vein and the internal and external carotid arteries. The 

 commencement of the external jugular vein, the posterior 

 facial vein, and the cervical branch of the facial nerve emerge 

 from this part of the surface. Immediately above the digastric 

 groove, close to the medial border, the external carotid enters 

 the gland ; and directly lateral to the upper end of the groove 

 for the styloid process the facial nerve passes into the gland 

 substance. The dissector should note that the postero-medial 

 surface of the gland is separated from the upper parts of the 

 internal jugular vein and the internal carotid artery, and from 



Anterior border of upper extremity 

 Area for cartilage of external meatus 



Area for bone of external meattis 

 Postero-medial border of upper end 



Mastoid area 



Styloid area- 

 Facial nerve-- 

 Posterior auricular artery. - 

 Ridge between digastric- 

 and sterno-mastoid areas 



External carotid artery l|H[ 



~ 



Posterior border^ 

 Sterno-mastoid groove' f"ji 



External jugular vein'' 

 FiG. 108. Parotid Gland, postero-medial aspect. 



the last four cerebral nerves by the posterior belly of the 

 digastric, the styloid process and the muscles attached to it. 



The medial border of the gland lies in the angle between 

 the postero-medial and the anterior boundaries of the parotid 

 space, where the styloid process, the stylo-hyoid muscle, and 

 the posterior belly df" the digastric disappear under cover of 

 the posterior border of the internal pterygoid muscle; and 

 from it a process, the pterygoid lobe, usually projects anteriorly, 

 for a short distance, between the internal pterygoid and the 

 inner surface of the ramus of the mandible. Through the 

 base of this process the external carotid passes from the 

 postero-medial to the antero-medial surface of the gland. 



The Antero-medial Surface. The medial part of the 



ii 17 c 



