270 



HEAD AND NECK 



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 : 



The Deep Auricular Artery. This small vessel pierces 

 the anterior wall of the external acustic meatus to supply 

 the skin which lines it, and also the superficial part of the 

 tympanic membrane. 



The Meningeal and Tympanic Branches proceed upwards 

 under cover of the external pterygoid muscle, and, therefore, 

 cannot be fully studied until that muscle is reflected. 



The Inferior Alveolar Artery arises opposite the middle 

 meningeal, and runs downwards, upon the spheno-mandibular 

 ligament, to enter the mandibular foramen. It is generally 

 accompanied 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 is carried downwards and anteriorly, with the 

 corresponding 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 

 pterygoid muscles. The Deep Temporal Branches are two in 

 number anterior and posteriory they pass upwards in the 

 temporal fossa, between the bony wall of the cranium and the 

 temporal muscle. They supply twigs to the temporal muscle, 

 and they anastomose with the middle temporal artery. The 

 Buccinator Branch accompanies the buccinator nerve, and 

 is distributed to the buccinator muscle and the mucous 



