560 TEXT-BOOK OF PHYSIOLOGY. 



tition, mastication, and articulation, especially in the pronunciation 

 of the consonantal sounds. In hemiplegia, complicated with paraly- 

 sis of the tongue from injury to the hypoglossal tract, the opposite 

 side of the tongue is involved in the paralysis. On protrusion of 

 the tongue the tip is deviated to the paralyzed side, due to the 

 unopposed action of the muscle of the opposite side. 



15. 



FIG. 257. DISTRIBUTION OF THE HYPOGLOSSAL NERVE. i. Root of the fifth nerve. 

 2. Ganglion of Gasser. 3, 4, 5, 6, 7, o, 10, 12. Branches and anastomoses of the 

 fifth nerve, n. Submaxillary ganglion. 13. Anterior belly of the digastric 

 muscle. 14. Section of the mylo-hyoid muscle. 15. GLOSSO-PHARYNGEAL NERVE. 

 16. Ganglion of Andersch. 17, 18. Branches of the glosso-pharyngeal nerve. 

 19, 19. Pneumogastric. 20, 21. Ganglia of the pneumogastric. 22, 22. Superior 

 laryngeal branch of the pneumogastric. 23. Spinal accessory nerve. 24. Sublin- 

 gual nerve. 25. Descendens noni. 26. Thyro-hyoid branch. 27. Terminal 

 branches. 28. Two branches, one to the genio-hyo-glossus and the other to the 

 genio-hyoid muscle. (Sappey.) 



Function. The hypoglossal nerve transmits nerve impulses 

 from its center of origin to the intrinsic and extrinsic muscles of the 

 tongue, endowing them with motility. The coordinate activity of 

 these muscles favorably assists mastication, articulation, and deg- 

 lutition. 



