TEMPORAL AND INFRATEMPORAL REGIONS 173 



pterygoid muscles. In that case the vessel makes a bend 

 laterally, between the heads of the external pterygoid muscle 

 before entering the pterygo-palatine fossa. 



The branches of the internal maxillary artery are classified 

 according to the portion of the vessel from which they spring. 

 Only one branch of the third part, viz. the posterior superior 

 alveolar artery, can be studied in this dissection. Those 

 arising from the first and second parts are : 



FROM THE FIRST PART. 



i. Arteria auricularis profunda. 



i 2. Arteria tympanica. 



| 3. Arteria meningea media. 



4. Ramus meningeus accessorius. 



5. Arteria alveolaris inferior. 



FROM THE SECOND PART, 



1. Arteria masseterica. 



2. Kami pterygoidei. 



3. Arterise temporales profundae. 



4. Arteria buccinatoria. 



Arteria Auricularis Profunda. The deep auricular artery 

 is a small vessel which pierces the anterior wall of the external 

 acoustic meatus to supply the skin which lines the meatus, 

 and also the superficial part of the tympanic membrane. 



Artericz Meningea Media et Tympanica Anterior. The 

 middle meningeal and the anterior tympanic branches pass 

 upwards under cover of the external pterygoid muscle, 

 and, therefore, cannot be fully studied until that muscle is 

 reflected. 



Arteria Alveolaris Inferior. The inferior alveolar artery 

 arises opposite the middle meningeal, and runs downwards, 

 along the lateral surface of the spheno-mandibular ligament, 

 to enter the mandibular foramen. It is generally accom- 

 panied by two venae comites, and it is placed posterior to the 

 inferior alveolar nerve. Just before entering the foramen, 

 the inferior alveolar artery gives off the slender mylo-hyoid 

 branch^ which runs downwards and forwards, with the corre- 

 sponding nerve, upon the deep aspect of the mandible, to the 

 digastric triangle of the neck. 



The branches from the second part are given off for the 

 supply of the neighbouring muscles. The Masseteric passes 

 horizontally, posterior to the temporal muscle, with the nerve 

 of the same name, and has been seen entering the masseter 

 muscle. The Pterygoid Branches are irregular twigs to the 



