283° 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. 
Fic, 120,—-BRANCHES OF EXTERNAL CAROTID ARTERY. 
#, common carotid; 4, branch to larynx; ¢, internal carotid; @, lingual; ¢, ex- 
ternal carotid; 7, posterior auricular; g, external maxillary; 4, superficial temporal; 
z, internal maxillary; 7, inferior alveolar; 4, middle meningeal; /, carotid plexus; 7, 
branch to temporal muscle; 7, ophthalmic; o, infraorbital; #, 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. genio- 
hyoideus; 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 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. 120, 0) and the sphenopalatine arteries, 
Branches of the internal maxillary artery and of the carotid 
plexus: 
1. A. alveolaris inferior (Fig. 120, 7).—The inferior alveo- 
Jar (or inferior dental) artery leaves the inferior maxillary just 
