THE SUPERFICIAL TEMPORAL ARTERY. 745 



Branches. — In addition to branches to the parotid gland and to neighboring muscles, it 

 gives rise to the stylo-mastoid artery (a. stylomastoidea). This vessel enters the stylo-mastoid 

 foramen and traverses the facial canal (aqueduct of Fallopius) as far as the point at which the 

 hiatus Fallopii passes off from it. During its course through the canal it gives off branches to 

 the mucous membrane lining the mastoid cells, to the stapedius muscle, and to the mucous 

 membrane of the middle ear, those twigs which pass to the inner surface of the tympanic mem- 

 brane anastomosing with the tympanic branch of the internal maxillary. Arrived at the hiatus 

 Fallopii, the artery accompanies the great superficial petrosal • nerve through that canal and 

 enters the cranium, supplying the dura mater and anastomosing with branches of the middle 

 meningeal artery. 



Variations.— The stylo-mastoid artery may arise from the occipital or its place may be 

 taken by the petrosal branch of the middle meningeal, with which the stylo-mastoid normally 

 anastomoses. 



9. The Superficial Temporal Artery. — The superficial temporal artery 

 (a. temporalis superficialis) ( Fig. 693) is the continuation of the external carotid after 

 it has given off the internal maxillary. At its origin it is embedded in the substance 

 of the parotid gland, and is directed upward over the root of the zygoma and imme- 

 diately in front of the pinna. After ascending a short distance, usually about 2 cm. , 

 upon the aponeurosis covering the temporal muscle, it divides into an anterior and a 

 posterior branch, which, diverging and branching repeatedly, pass upward over the 

 temporal and occipito-frontal aponeuroses almost to the vertex of the skull, anasto- 

 mosing with the supra-orbital branches of the ophthalmic branch of the internal 

 carotid, with the posterior auricular and occipital branches of the external carotid, 

 and with the artery of the opposite side. 



Branches. — 



[a) Parotid branches (rami parotide! ), small branches to the parotid gland. 



{d) Articular branches to the temporo-mandibular articulation. 



{c) Muscular branches to the masseter muscle. 



(d) The anterior auricular branches (rami auriculares anteriores) supply the outer surface 

 of the pinna and the outer portion of the external auditory meatus. 



(e) The transverse facial artery (a. transversa faciei) arises just below the main stem of the 

 artery, crosses the zygoma, and is directed forward parallel with the zygoma and between it 

 and the parotid duct. It gives off branches to neighboring muscles and to the integument of 

 the cheek, and anastomoses with the masseteric branches of the facial and with the buccal, 

 alveolar, and infra-orbital branches of the internal maxillary. 



{/) The middle deep temporal (a. temporalis media) arises just above the zygoma, and 

 after perforating the temporal aponeurosis and muscle, it ascends upon the surface of the skull 

 to anastomose with the deep temporal branches of the internal ma.xillary artery. 



{g-) The orbital branch (a. zygomaticoorbitalis) runs forward along the upper border of the 

 zygoma, supplying the orbicularis palpebrarum and also sending branches into the cavity of 

 the orbit. 



Anastomoses. — The superficial temporal artery makes extensive anastomoses 

 in the scalp with its fellow of the opposite side, with the occipital and posterior auricu- 

 lar branches of the external carotid, and with the supra-orbital branch of the oph- 

 thalmic. By means of the transverse facial it makes anastomoses with the facial and 

 internal maxillary arteries. 



Variations. — The principal variations of the superficial temporal are its division into the 

 terminal branches below the level of the zygomatic arch and the absence of its posterior ter- 

 minal branch ; in the latter case the area of distribution of the posterior branch is supplied by, 

 the posterior auricular or the occipital artery. 



Practical Considerations. — The superficial temporal artery may require 

 ligation on account of wound of the vessel, or of one of its branches, or in cases of 

 aneurism. It or one of its chief subdivisions used frequently to be selected for the 

 now rare operation of arteriotomy. The vessel never becomes very superficial imme- 

 diately after emerging from beneath the upper part of the parotid. In the first por- 

 tion of its track of ascent its pulsations are difficult to perceive. In the presence of 

 the least swelling of the region they become incapable of serving as a guide for the 

 incision (Farabeuf). 



