72 



TOPOGRAPHICAL ANATOMY OF THE 



the great cornu of the hyoid bone, and on to its lateral face, results in 

 a partial separation of a lateral compartment from the main cavity. 

 The lateral compartment embraces not more than a third of the total 

 cavity. 



The dorsal relations of the diverticulum are the base of the 

 cranium, the atlanto-occipital articulation, the longus capitis and the 

 ventral straight muscle of the head. Ventrally it is in contact with the 

 pharynx and the beginning of the oesophagus. The structures related 



M. rectus 

 capitis lateralis. 



M. longus colli.- ^ 



A. carotis interna 



N. vagus. - 



Hvoid bone. 



Eustachian tube. 



^M. pterygoideus 

 internus. 



■M. stylopharyngeus. 

 A. maxillaris externa. 



N. glossopharyngeus. 

 N. hypoglossus. 

 M. chondropharyngeus. 



M. longus capitis. 



M. thyreopharyngeus. 

 A. carotis externa. 

 Fig. 22.— The diverticulum of the auditory (Eustachian) tube opened to 

 show its lateral wall. 



to its lateral face are numerous and important, and may be summar- 

 ised as follows: — The pterygoid, jugulo-mandibular, digastric, stylo- 

 hyoid, jugulo-hyoid, tensor veli palatini and levator veli palatini 

 muscles ; the mandibular articulation ; the parotid and submaxillary 

 glands; the external carotid, superficial temporal, external maxillary 

 and internal maxillary (first part) arteries and branches thereof; the 

 internal maxillary vein and certain of its tributaries; the facial, glosso- 

 pharyngeal, hypoglossal and cranial laryngeal nerves, as well as the 

 mandibular nerve and its main branches. The vagus and accessory 

 nerves, the sympathetic nerve trunk and its cranial cervical ganglion, 



