PRINCIPAL ARTERIES OF THE HEAD 195 



Note. The internal carotid makes four sharp turns after entering the 

 carotid canal in the petrous bone, and by this means the force of the current 

 in this large vessel is modified before it reaches the delicate tissues of the 

 brain. The internal jugular vein and vagus nerve accompany it in the neck. 



The external carotid artery supplies the face, and front of the 

 neck and scalp (Fig. 133). 



Principal branches. Superior thyroid, to the thyroid gland 

 and larynx. Lingual, to the tongue and tonsil. Facial (or external 

 maxillary) to the face, soft palate and tonsil. Occipital, to the 

 back of the head and neck. 



FIG. 133. FACIAL, TEMPORAL AND OCCIPITAL ARTERIES. 



Clinical notes. The external maxillary (facial) artery runs toward the 

 bridge of the nose. It sends two labial arteries to the borders of the lips; 

 the one in the upper lip supplies a branch to the septum of the nose, therefore, 

 compression of the upper lip will sometimes stop "nose-bleed." 



The lingual artery ends at the tip of the tongue, in a branch (ranine) which 

 might be severed in cutting too freely for "tongue-tie." 



Having given off its branches, the external carotid passes into 

 the substance of the parotid gland and divides into the temporal 

 and internal maxillary. 



The temporal passes through the parotid gland and across the 

 zygoma to the side of the head, supplying temporal branches to the 

 scalp. The internal maxillary runs between the muscles of mas- 

 tication (in the infratemporal fossa) to the deep parts of the face, 

 including the nose and pharynx. The dental arteries are all de- 

 rived from this vessel. 



