THE LINGUAL REG-ION. 61 



SURGICAL ANATOMY OF THE LINGUAL REGION". - 



The tongue completely occupies tKe^-ea,vity of the 

 mouth when it is shut, and is attached for the posterior 

 two-thirds of its volume to the hyoid bone and inferior 

 maxillary bone, by its extrinsic muscles and membranes ; 

 by means of the stylo-glossus it is attached to the styloid 

 process, and by the palato-glossus to the palatine arch. 

 It is at this portion of the organ that the nerves and 

 arteries enter and its veins leave it. Beneath it, in the 

 middle line, is a fold of mucous membrane, the frsenum, 

 on either side of which are the orifices of Wharton's 

 ducts, and those of the sublingual glands, or ducts of 

 Riviniani, lie in the fossa between the tongue and max- 

 illary bone. 



Structure. The mucous membrane is very adherent to 

 the underlying structure, particularly on the dorsurn 

 and sides ; on the under surface, however, it is less so, 

 there being a cellular layer between it and the sublingual 

 muscles. The mucous membrane is freely supplied with 

 papillae ; the sides and tip with fungiform, almost its 

 entire surface with filiform, and the posterior part of its 

 dorsum with the Y-shaped series of the circumvallate. 

 There are a considerable number of glands lying in this 

 tissue, which give rise to the development of that en- 

 cysted tumor known as ranula. An enlargement of the 

 bursa existing between the hyoid attachment of the 

 genio-hyoglossi, by its enlargement and protrusion be- 

 neath the tongue, may be mistaken for ranula. 



The muscles are both intrinsic and extrinsic. The 

 intrinsic or linguales are two symmetrical bundles of 

 muscular fibre, separated from each other by a fibrous 

 septum, occasionally cartilaginous, and these muscular 



