738 



THE NESVES. 



12 Twelfth Pair, or Great Hypoglossal Nerves. 

 (Figs. Ill, 22 ; 338, 5 ; 342.) 

 The qreat, or simply the hjpoglossal nerve, is exclusively motor, and 

 animates the muscles of the tongue. 



Fig. 342. 



DEEP NERVES OF THE HEAD. 

 1, Superior maxillary nerve at its exit from the foramen lacerum ; 2, Trunk of the 

 masseteric ; 3, Trunk of the subzygomatic ; 4, Buccal ; 5, Lingual or gustatory ; 

 6, Chorda tympani ; 7, Inferior maxillary, cut near "where it enters the maxillo- 

 dental canal; 8, Trunkof themylo-hyoideus ; 9, Pterygoid; 10, Glosso-pharyngeal ; 

 11, Its pharyngeal branch; 12, Its lingual branch; 13, Pneumogastric ; 14, 

 Superior laryngeal branch of that nerve ; 15, Its pharyngeal branch ; 16, Spinal 

 accessory of Willis ; 17, Great hypoglossal ; 18, Origin of the cervical cord of the 

 great sympathetic; 19, The same after its union with the pneumogastric. — A, 

 Common carotid artery ; B, Accessory thyroid artery ; C, Thyro-laryngeal artery ; 

 D, Origin of the internal carotid artery — the vessel is concealed by the guttural 

 pouch ; E, Occipital artery ; F, External carotid artery ; G, Internal maxillary 

 artery ; H, Pharyngeal artery (drawn too large) ; /, External maxillary artery ; 

 /, Lingual artery ; A", Origin of the maxillo-muscular artery ; L, Posterior 

 auricular artery ; M, Trunk or origin of the superficial temporal artery ; 0, 

 Inferior dental artery ; P, Posterior deep temporal artery ; Q, Anterior deep 

 temporal artery ; R, Maxillary gland ; S, Wharton's duct ; 7', Sublingual gland. 

 The letter N placed at the upper end of the large coi-nu of the hyoid bone has 

 no signification. 



Origin — It originates at the lower face of the medulla oblongata, from 



