THE INTERNAL MAXILLARY ARTERY 545 



skin. It anastomoses with the posterior branch of the superficial temporal arter}-. The 

 branches to the pinna not only supply the back of that structure, but some perforate the 

 cartilage, and others turn over its free margin to supply the lateral surface; there they anasto- 

 mose with the anterior auricular branches from the temporal. 



(3) The occipital branch [ramus occipitaUs] passes upward and backward, crossing the 

 aponeurotic insertion of the sterno-mastoid muscle. It gives a branch to the posterior belly 

 of the epicranius (occipito-frontahs), and anastomoses with the occipital artery. 



8. THE SUPERFICIAL TEMPORAL ARTERY 



The superficial temporal artery [a. temporalis superficialis] (fig. 445), is the 

 smaller of the two terminal divisions of the external carotid, though apparently 

 the direct continuation of that vessel. It arises opposite the neck of the man- 

 dible and, under cover of the parotid gland, passes upward in the interval be- 

 tween the condyle and the external auditory meatus to the zygoma, lying on the 

 capsule of the temporo-mandibular joint. Thence it ascends over the posterior 

 zygomatic root and the temporal aponeurosis for about 4 or 5 cm. (1| or 2 in.), and 

 there divides into frontal and parietal branches. It is surrounded by a dense 

 plexus of sympathetic nerves, and is accompanied by the auriculo-temporal nerve, 

 which lies beneath and generally a little behind it. It is crossed by the temporal 

 and zygomatic brandies of the facial nerve, and by the auricularis anterior (attra- 

 hens aurem) muscle. As it crosses the zygoma it can be readily felt pulsating 

 immediately in front of the ear, and in this situation can be compressed against the 

 bone. It is here quite superficial, being merely covered by the integuments and a 

 delicate prolongation from the cervical fascia (fig. 445). 



Branches of the Superficial Temporal Artery 



The branches of the superficial temporal artery are: — (1) The parotid; (2) 

 the transverse facial; (3) the anterior auricular; (4) the zygomatico-orbital; 

 (5) the middle temporal; (6) the frontal; (7) the parietal. 



(1) The parotid branches [rami parotidei] are small twigs given off in the substance of the 

 parotid gland. 



(2) The transverse facial [a. transversa faciei] is the largest branch of the temporal. It 

 sometimes arises from the external carotid as a common trunk with the temporal. It is at 

 first deeply seated in the substance of the parotid gland, but soon emerging from the upper part 

 of the anterior border of the gland known, courses transversely across the masseter muscle 

 about a finger's breadth below the zygoma. The parotid duct runs below it, and the zygomatic 

 (infraorbital) branches of the facialnerve above it. It supplies the parotid gland, the masseter 

 muscle, and the skin of the face, and anastomoses with the infraorbital, the buccal, and the ex- 

 ternal maxillary (facial) arteries. 



(3) The anterior auricular branches [rami auriculares anteriores] are three or four in number 

 and supply the tragus, the pinna, and the lobule of the ear, and to some extent the external 

 auditory meatus. 



(4)'^The zygomatico-orbital artery [a. zygomaticoorbitaUs] (fig. 445), at times a branch of 

 the deep temporal, passes forward along the upper border of the zygoma in the fat between 

 the superficial and deep layers of the temporal aponeurosis, and, after giving branches to the 

 orbicularis oculi, sends one or more twigs into the orbit through foramina in the zygomatic 

 (malar) bone to anastomose with the lacrimal and palpebral branches of the ophthalmic. 



(5) The middle temporal artery [a. temporalis media] (fig. 453), arises just above the 

 zygoma, and, perforating the temporal aponeurosis and temporal muscle, ascends on the squa- 

 mous portion of the temporal bone, and anastomoses with the posterior deep temporal artery. 



(6) The frontal or anterior terminal branch [ramus frontalis] ramifies tortuously in an up- 

 ward and forward direction over the front part of the skull. It hes first between the skin and 

 temporal fascia and then between the skin and epicranial aponeurosis. It supplies the anterior 

 belly of the epicranius (occipito-frontahs) and the orbicularis oculi muscles, and anastomoses 

 with the supraorbital and frontal branches of the ophthalmic, and with the corresponding 

 artery of the opposite side. The secondary branches given off from this vessel to the scalp 

 run from before backward. 



(7) The parietal or posterior terminal branch [ramus parietahs] ramifies on the side of the 

 head between the skin and temporal fascia. Its branches anastomose, in front with the anterior 

 terminal branch; behind, with the posterior auricular and occipital arteries; and above, across 



. the vertex of the skull, with the corresponding artery of the opposite side. 



9. THE INTERNAL ISIAXILLARY ARTERY 



The internal maxillary artery [a. maxillaris interna] (fig. 451) is the larger of 

 the two terminal divisions of the external carotid. It arises opposite the neck of 

 the mandible in the substance of the parotid gland, and, passing first between the 

 mandible and the spheno-mandibular ligament and then between the external 



