1134 



THE DIGESTIVE SYSTEM. 



and lined on the other, by fascia. The covering layer is specially known as the fascia 

 parotideomasseterica (O.T. parotid fascia) and both it and the lining layer are derived 

 from the deep cervical fascia, which divides to enclose the gland. The parotideo-masseteric 

 fascia is connected, on the surface, above to the zygoma ; posteriorly, to the acoustic meatus 

 and anterior border of the sterno-mastoid ; below, it is continuous with the deep cervical 

 fascia, and anteriorly it passes over the masseter, and blends with the fascia bucco- 

 pharyngea. The fascia forms a lining for the recess, and is united above to the peri- 

 osteum over the acoustic meatus and posterior part of the glenoid fossa ; medially it is 



Internal jugular vein Hypoglossal nerve 



Accessory nerve 

 Digastric muscle 



Stylo-hyoid 

 Glosso- 



pharyngeal nerve 

 Parotid glands 



Posterior 



facial vein 



External carotid 



artery 



Styloglossus 



Ascending 



palatine artery 



Internal pterygoid 



Epiglottis 



Glosso-epiglottic 

 fold 



Masseter 



Pharyngeal 

 portion of tongue 



Internal carotid artery 

 Vagus nerve 



Sympathetic trunk 



Ascending pharyngeal artery 

 Dens 



Pungiform papilla 

 Buccinato: 



_, Retro-pharyngeal 

 ' lymph gland 



Superior 



constrictor muscle 

 Pharyngo-palatine 

 arch 



- Palatine tonsil 



Phary ngo -epigl ottic 

 fold 



Glosso-palatine 

 arch 



Vallate papillae 



Raphe of tongue 



mical papillae 



Fungiform papilla 



FIG. 896. HORIZONTAL SECTION THROUGH MOUTH AND PHARYNX AT THE LEVEL OF THE PALATINE TONSILS 



The stylopharyngeus, which is shown immediately to the medial side of the external carotid artery, and the 

 prevertebral muscles, are not indicated by reference lines. 



connected to the styloid process ; whilst below it joins the deep cervical fascia. Takei 

 together, the two layers form a definite capsule which completely encloses the gland 

 In connexion with the lower and anterior part of this capsule is developed a specia 

 flat band, the stylo-mandibular ligament, which passes downwards and laterally fror : 

 the styloid process to the angle of the mandible. It separates the anterior part c 

 the parotid gland from the posterior border of the internal pterygoid muscle ; perhap 

 occasionally, also, from the upper and posterior part of the submaxillary gland. 



Shape and Relations of the Parotid Gland. The main mass of the paroti 

 gland is three-sided (Fig. 896), the three surfaces being superficial, anterior, an 

 posterior. 



Superficial Surface. This surface is somewhat triangular in form, thoug 

 irregular in outline. Its long posterior border lies in front of the extern 

 acoustic meatus, and the sterno-mastoid muscle. Its superior border lies below th 

 zygomatic arch, and the inferior border passes irregularly upwards and anteriorly t 



