88 



PRACTICAL ANATOMY. 



The nerves to the pterygoid muscles are from the third division of the fifth 

 nerve. (Fig. 53.) The blood-supply comes from the internal maxillary artery, 

 second stage. (Fig. 51.) 



Describe the internal maxillary artery. (Fig. 51.) 



First Stage. Behind the neck of the mandible. In this stage it gives off: 



1. The inferior dental artery to the inferior teeth. 



2. The great meningeal artery to the dura and calvarium. 



3. The small meningeal artery to the dura mater. 



4. The deep auricular branch to external canal. 



5. Tympanic, to the membrana tympani. 



Temporal 



Buccinator 



FIG. 52. THK TEMPORAL MUSCLE. 



The second stage of the artery gives off branches to muscles of mastication : 



1. Deep temporal branches to temporal muscles. 



2. Buccal branch to the buccinator muscle. 



3. Internal pterygoid branch to internal pterygoid muscle. 



4. External pterygoid branch to external pterygoid muscle. 



5. Masseteric branch, to the masseter. 



The second or pterygoid stage lies on the outer surface of the external ptery- 

 goid muscle, under cover of the temporal muscle and the ramus of the mandible. 



The third stage of the artery gives off these branches : 



I. The posterior superior dental artery. This is confusing, and requires an 

 explanation. The dental branches supply the teeth. They enter the posterior 

 superior dental canals, through foramina on the posterior surface of the body of 

 the superior maxilla. The alveolar branches supply the gums. Some branches 

 supply the mucous membrane of the antrum ; these might be called antral 

 branches. 



