288 



THE CIRCULATORY SYSTEM. 



branches of the plexus enters the skull through the orbital 

 fissure, lying beside the hypophysis ; it divides in the manner 

 described below. 



FIG. 120. BRANCHES OF EXTERNAL CAROTID ARTERY. 

 a, common carotid; b, branch to larynx; c, internal carotid; d, lingual; e, ex- 

 ternal carotid; _/, posterior auricular; g, external maxillary; A, superficial temporal; 

 i, internal maxillary; _/, inferior alveolar; k, middle meningeal; /, carotid plexus; m, 

 branch to temporal muscle; n, ophthalmic; o, infraorbital; p, lesser palatine. I, M. 

 constrictor pharyngis inferior; 2, M. sternothyreoideus; 3, M. sternohyoideus ; 4, M. 

 thyreohyoideus; 5? M. constrictor pharyngis medius; 6, M. hyoglossus; 7, M. genio- 

 hyoideus; 8. M. genioglossus ; 9, M. digastricus; 10, Mm. pterygoidei externus and 

 internus (cut); II, M. temporalis (cut). 



Beyond the carotid plexus a main trunk which may be con- 

 sidered 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. 1 20, o) and the sphenopalatine arteries. 



Branches of the internal maxillary artery and of the carotid 

 plexus: 



i . A. alveolaris inferior (Fig. 1 20, /). The inferior alveo- 

 lar (or inferior dental) artery leaves the inferior maxillary just 



