346 



HANDBOOK OF PHYSIOLOGY. 



THE TONGUE. 



Structure. The tongue is a muscular organ covered by mucous 

 membrane. The muscles, which form the greater part of the substance 

 of the tongue (intrinsic muscles) are termed linguales; and by these, 



Fig. 240. Papillar surface of the tongue, with the fauces and tonsils. 1,1, clrcumvallate pa 

 pillae, in front of 2, the foramen caecum; 3, fungiform papilla? ; 4, filiform and conical papillae ; 5, 

 transverse and oblique rugae ; 6, mucous glands at the base of the tongue and in the fauces ; 7, tonsils; 

 8, part of the epiglottis ; 9. median glosso-epiglottidean fold (fraenum epiglottidis). (From Sappey.) 



which are attached to the mucous membrane chiefly, its smaller and 

 more delicate movements are chiefly performed. 



By other muscles (extrinsic muscles), as the genio-hyoglossus, the 

 styloglossus, etc., the tongue is fixed to surrounding parts, and by this 

 group of muscles its larger movements are performed. 



The mucous membrane of the tongue resembles other mucous mem- 



