2o8 HEAD AND NECK 



Arteria Maxillaris Interna. The commencement of the 

 internal maxillary artery, from the termination of the external 

 carotid, between the neck of the mandible and the antero- 

 medial surface of the parotid gland, has been seen already, and 

 the artery has been traced through the infratemporal region 

 to the pterygo-palatine fossa, where its terminal branches will 

 be dissected at a later period. 



Arteria Temporalis Superficialis. Like the internal 

 maxillary, the superficial temporal artery commences between 

 the neck of the mandible and the antero-medial surface of 

 the parotid gland. It passes upwards, and, as it emerges 

 from under cover of the upper end of the parotid gland, it 

 pierces the parotid fascia, crosses superficial to the posterior 

 end of the zygomatic arch, and enters the superficial fascia of 

 the scalp, in which it ascends, on the superficial surface of the 

 temporal fascia, and anterior to the auricle (Figs. 51, 76). It 

 breaks up into two branches, frontal and parietal. The two 

 branches anastomose with each other and with their fellows of 

 the opposite side. The frontal branch anastomoses with the 

 supra-orbital and frontal branches of the ophthalmic also, and 

 the parietal branch anastomoses with the posterior auricular 

 and the occipital arteries. Whilst it is still under cover of 

 the parotid it gives branches to the gland ; anterior auricular 

 branches to the auricle ; the transverse facial, which passes 

 along the lower border of the zygomatic arch, across the 

 masseter. As the superficial temporal crosses the zygoma it 

 gives off a zygomatico-orbital branch, which runs to the lateral 

 border of the orbit, and a middle temporal branch, which 

 perforates the temporal fascia and anastomoses in the tem- 

 poral fossa with the deep temporal branches of the internal 

 maxillary. The course of the middle temporal branch (Fig. 

 76) and the distribution of the terminal branches have been 

 followed in earlier stages of the dissection (pp. 48, 169). 



Dissection. Divide the posterior belly of the digastric 

 immediately below its origin, and turn it downwards and 

 forwards towards the hyoid bone ; then examine the stylo- 

 pharyngeus muscle. It may be necessary to cut the occipital 

 and posterior auricular arteries in order to gain free access to 

 the deeper parts, but that should not be done unless it is un- 

 avoidable. Care must be taken whilst cleaning the stylo- 

 pharyngeus to avoid injuring the glosso-pharyngeal nerve, 

 which turns round its posterior border and crosses its superficial 

 surface. 



