504 



DISSECTION OF THE HEAD. 



Supraorbital 

 nerve : 



its two cuta- 

 neous and 



palpebral 

 branches. 



Supratroch- 

 lear nerve : 



palpebral 

 branch. 



Temporal 

 nerves : 



of superior 

 maxillary ; 



of inferior 

 maxillary, 



its auricular 

 branch ; 



and of facial 

 nerve. 



Posterior 

 auricular^ 

 nerve has 



The half of the head in front of the ear receives branches from the 

 three trunks of the fifth cranial nerve, and twigs to the muscles 

 from the facial nerve. The skin of the hinder part of the head is 

 supplied by spinal nerves (anterior and posterior primary branches) ; 

 and close behind the ear, there is a muscular offset of the facial or 

 seventh cranial nerve. 



The SUPRAORBITAL NERVE (fig. 186), comes from the first trunk 

 of the fifth nerve, and escapes from the orbit with its companion 

 artery. It is placed at first beneath the orbicularis palpebrarum 

 and frontalis muscles, and here gives offsets to these as well as to 

 the pericranium. In the orbicularis a communication is established 

 between this and the facial nerve. Finally the nerve ends in two 

 cutaneous branches. 



The inner of these soon pierces the frontalis, and reaches upwards 

 as high as the parietal bone. The outer branch is of larger size, 

 and perforating the muscle higher up, extends over the head as far 

 as the ear. 



As the nerves escapes from the supraorbital notch it furnishes 

 some palpebral filaments to the upper eyelid. 



At the inner angle of the orbit is the small SUPRATROCHLEAR 

 NERVE (fig. 186), from the same trunk. It ascends to the forehead 

 close to the bone and, piercing the muscular fibres, ends in the 

 integument. Branches are given from it to the orbicularis and 

 corrugator supercilii, and some palpebral twigs enter the upper 

 eyelid. 



The SUPERFICAL TEMPORAL NERVES are derived from the second 

 and third trunks of the fifth nerve, and from the facial nerve. 



The TEMPORAL BRANCH OF THE SUPERIOR MAXILLARY NERVE 



(second trunk of the fifth) is a slender twig (fig. 186), from the 

 temporo-malar nerve, which perforates the temporal aponeurosis 

 about a finger's breadth above the zygomatic arch. When cuta- 

 neous, the nerve is distributed on the fore part of the temple, and 

 communicates with the facial nerve, also sometimes with the next. 



The AURICULO-TEMPORAL NERVE (fig. 186, accompanying d), a 

 branch of the inferior maxillary (third trunk of the fifth), makes its 

 appearance with the temporal artery in front of the ear. As soon as 

 it emerges from beneath the parotid gland, it divides into two terminal 

 branches. The posterior is the smaller of the two, and supplies 

 the integument above the ear. The anterior branch ascends verti- 

 cally to supply the skin as far as the upper limit of the temporal 

 fossa. The nerve also furnishes an auricular branch (upper) to the 

 fore part of the ear above the auditory meatus. 



The TEMPORAL BRANCHES OF THE FACIAL NERVE are directed 

 upwards over the zygomatic arch and the temporal aponeurosis to the 

 orbicularis palpebrarum, corrugator supercilii and frontalis muscles : 

 they will be described with the dissection of the facial nerve. 



The POSTERIOR AURICULAR NERVE (fig. 186) lies behind the ear 

 with the artery of the same name. It arises from the facial nerve 

 close to the stylo-mastoid foramen, and ascends in front of the 

 mastoid process. Soon after the nerve becomes superficial it 



