124 THE SURGICAL ANATOMY OF THE HORSE 



T/w Blood-Supply. — The superficial temporal artery divides beneath 

 the parotid gland and just below the condyle of the inferior maxilla, 

 into the transverse facial and anterior auricular arteries. 



The anterior auricular artery takes an upward course behind the 

 temporo-maxillary joint upon the capsular ligament of which it lies. It 

 is distributed to the muscles and skin at the base of the concha, and 

 terminates in the temporal muscle. 



The posterior auricular artery is given off as a collateral branch of 

 the external carotid. It commences under the parotid gland on the 

 outer aspect of the styloid cornu of the hyoid bone. After a short 

 course, during which it passes on to the occipito-styloid muscle, it 

 splits up into anterior and posterior divisions. The former takes a 

 course upwards, and is distributed to the concha behind the entrance 

 to the ear. It also gives off branches to the base of the ear, and a 

 long slender branch which is distributed on the inner aspect of the 

 concha. 



The anterior auricular vein is slightly larger than the artery which 

 it accompanies, and it assists in the formation of the superficial 

 temporal vein. The veins which accompany the divisions of the 

 posterior auricular artery unite to form two vessels. These again 

 unite to form the posterior auricular vein, which descends at first on 

 the outer aspect of the parotid gland, and then dips into the gland 

 within which it empties itself into the jugular. 



The Nerve-Supply. — The anterior auricular nerve is a branch of the 

 seventh cranial nerve, from which it is given off beneath the parotid 

 gland. This nerve runs over the zygomatic process and down the 

 anterior aspect of the body of the frontal bone, to terminate near 

 the nasal canthus, where it pierces the levator labii superioris afeque 

 nasi muscle. During its course it distributes filaments to the parieto- 

 auriculares muscles. 



The middle auricular nerve is another branch of the seventh. It 

 passes upwards behind the downwardly projecting piece of the conchal 



