1350 



CLINICAL AND TOPOGRAPHICAL ANATOMY 



Of these, the veins can be seen just to one side; the arteries are close by, but deeper. Farther 

 out are two more or less distinct fringed folds, the plicca fimbriatae, running from behind forward 

 and, like the frenulum, disappearing before the tip. Between these and the frenulum are the 

 smaU apical mucous glands of Nuhn or Blandin. Farther back, at the junction of the mucous 

 membrane and the alveoli, are two other projections of the mucosa, the sublingual; under these 

 are the sublingual glands, the ranine veins, and, more deeply, Wharton's duct and the termina- 

 tion of the lingual nerve. The majority of the ducts of the sublingual gland (Rivinian) open on 

 the sublingual ridges. A single larger one, Bartholin's, opens with that of Wharton, or close to 

 it, on either side of the frenulum (fig. 1096). Dilatation of one of the Rivinian ducts, more fre- 

 quenth^ dilatation of a muciparous gland — and, much more rarely, dilatation of Wharton's duct 

 — constitutes a 'ranula.' 



The submaxillary gland can be felt nearer the angle of the jaw, lying between 

 its fossa and the mucous membrane, especially if pressure is made from outside. 

 The attachment of the genio-glossi can be felt behind the symphysis: the division 

 of the muscles allows the tongue to come well out of the mouth ; but when both 

 have to be divided, the tongue loses much of its steadiness, and may easily fall 



Fig. 1097. — Sebtion op the Skull and Brain in thf Median Plane. (Braune.) 



Falx cerebri 

 Superior sagittal sinus 



5 Inferior sagittal sinus 



Corpus callosum 



-^ — -v^ _' -^ i^ — i —TTrnj^r, ^ - Optic chiasma 



,V>~^ ' *^_J^ * -MP\ -M- Corpus mammiUare 



V^ ^^ ./ \ \j^^ Z*'^'*^^ Jii Occipital lobe of 



"^^ i_lcra/_>^^:MpoTs'''"'" 



^^^ ""^ " -^-^ Torcular Heropliili 

 Medulla oblongata 



Posterior ring of atlas 

 Body of epistropheus (axis) 



Hypophysis 

 Sphenoid bone 



Tuba auditiva — > 



Genio-glossus 

 Mylo-hyoid -^^^ 



Arytaenoideus muscle 

 Rima glottidus 



Thyreoid gland 

 Sterno-thyreoid muscle 



Body of second thoracic 

 vertebra 



back over the larynx during the administration of the anaesthetic or, later on, in 

 sleep. It should therefore be secured forward for a while with silk. For the 

 same reason, in removal of one-half of the mandible, part of this muscular 

 attachment should always be left, if possible. 



Turning now to the dorsum of the tongue, this shows two distinct parts: one, the anterior 

 two-thirds, Ihc buccal, is rich in i)apill;u; the other, the posterior, the pharyngeal, contains abun- 

 dant lymphoid follicles like the tonsil. This i)art possesses peculiar sensibility, as shown by 

 movements of tongue and palate when a depressor is placed too far back. The two parts 

 are separated l)y the \/-shai)cd arrangement of the vallate papilla;, with the apex turned back- 

 ward. Immediately bcliiud the apical vallate i)apilla is a small pit, the foramen ca;cum 

 which represents the ui)per remains of the thj'reoglossal tract, and may be the seat of lingual 

 thyreoid growths. While the tongue is mainlj' a muscular organ, the fine fatty connective tissue 

 in the septum and between the inus(!uhir bundles is the scat of that dangerous condition acute 

 glossitis, and of gummatous infiltration. While the mouth is widely open, the pterygo-man- 

 dibular ligament can he seen and felt l)encath the mucous membrane, behind the last molar 

 tooth. Ju.st below and in front of the lower attachment of this ligament the lingual nerve can 

 be felt lying close to the bone Ijelow tlio last molar. The simplest and surest method of dividing 

 the nerve here, to give relief from pain in in('ural)Ic carcinoma of t he tongue, is to draw the tongue 

 out of the mouth and expose the nerve where it lies superficially under the mucous membrane 

 thus made prominent between the side of the tongue and the gums, the centre of the incision 



