_f._ =A. maxillaris interna= (Fig. 119, _n_; Fig. 120, _i_).--The internal maxillary artery is the continuation of the external carotid. It turns caudad at the caudal end of the mandible, then passes craniad, lying dorsad of the pterygoid muscles (Fig. 120, 10), and against the medial surface of the mandible. It gives off the =inferior alveolar= artery (Fig. 120, _j_), then the =middle meningeal= (_k_), and then continuing mediad divides into three or four branches. The branches redivide, and the twigs form a complicated plexus, the =carotid plexus= (Fig. 120, _l_), which surrounds the maxillary division of the fifth nerve near its exit from the foramen rotundum. One of the larger branches of the plexus enters the skull through the orbital fissure, lying beside the hypophysis; it divides in the manner described below. [Illustration: FIG. 120.--BRANCHES OF EXTERNAL CAROTID ARTERY. _a_, common carotid; _b_, branch to larynx; _c_, internal carotid; _d_, lingual; _e_, external carotid; _f_, posterior auricular; _g_, external maxillary; _h_, superficial temporal; _i_, internal maxillary; _j_, inferior alveolar; _k_, middle meningeal; _l_, carotid plexus; _m_, branch to temporal muscle; _n_, ophthalmic; _o_, infraorbital; _p_, lesser palatine. 1, M. constrictor pharyngis inferior; 2, M. sternothyreoideus; 3, M. sternohyoideus; 4, M. thyreohyoideus; 5, M. constrictor pharyngis medius; 6, M. hyoglossus; 7, M. geniohyoideus; 8, M. genioglossus; 9, M. digastricus; 10, Mm. pterygoidei externus and internus (cut); 11, M. temporalis (cut).] Beyond the carotid plexus a main trunk which may be considered the continuation of the internal maxillary passes craniad, lying on the dorsal surface of the external pterygoid muscle; nearly opposite the molar tooth it divides into the =infraorbital= (Fig. 120, _o_) and the =sphenopalatine= arteries. Branches of the internal maxillary artery and of the carotid plexus: 1. =A. alveolaris inferior= (Fig. 120, _j_).--The inferior alveolar (or inferior dental) artery leaves the inferior maxillary just opposite the condyloid process of the mandible. It enters the mandibular canal by the mandibular foramen, along with the nerve of the same name, and traverses the canal, furnishing branches to the lower teeth. It emerges at the mental foramen, and its terminal branches are distributed to the chin, but a branch is continued in the bone beyond the mental foramen and supplies the incisor and canine teeth of the lower jaw. 2. =A. meningea media= (Fig. 120, _k_).--The middle meningeal is a large vessel which leaves the internal maxillary at about the same level as the inferior alveolar. It passes into the foramen ovale and ramifies in the dura mater. Its branches leave distinct impressions on the inner surface of the bones of the skull.