TONGUE. 



1133 



ing the anterior pillar of the fauces ; and 

 arrived at the sides of the tongue, it again 

 spreads out, and its fibres mingle with those 

 of the styloglossus, some of them passing 

 transversely into the medullary structure. It 

 lies immediately beneath the mucous mem- 

 brane, and in front of the tonsil. Action : To 

 constrict the fauces (hence its name, con- 

 strictor isthmi ffiiicinm) by depressing the soft 

 palate and raising the sides of the tongue. 



The styloglossus. A small slender muscle 

 arising by a pointed tendinous origin from the 

 inferior half of the styloid process of the tem- 

 poral bone, and also slightly from the stylo- 

 maxillary ligament. It passes downwards and 

 inwards to the base of the tongue, opposite to 

 which it expands and becomes flattened; a 

 few of its fibres bend inwards, the majority 

 being continued longitudinally along the side 

 of the tongue, where they may be traced to 

 near the apex, contributing to the formation 

 of the lateral lingual muscle. As they pass 

 forward, they mingle with those fibres of the 

 hyoglossus that have a similar direction, and 

 with the inferior lingual. Relations : Ex- 

 ternally, with the parotid and submaxillary 

 glands, the external carotid artery, the facial 

 artery, the Whartonian duct, the lingual 

 branch of the fifth nerve, and the stylomax- 

 illary ligament ; internally, with the stylo- 

 hyoid ligament, internal carotid, superior 

 constrictor of the pharynx, the jugular vein, 

 and hyoglossus muscle. Action: To retract 

 the tongue, to raise and expand its base, and 

 to render it concave from side to side by rais- 

 ing its borders. 



The hyoglossus. Flat, thin, and ascending 

 nearly vertically, this muscle approaches a 

 quadrilateral form ; but, from the dorsuin of 

 the tongue ascending as it passes forwards, 

 its anterior border is much larger than its 

 posterior. It arises from the posterior ex- 

 tremity, and from the superior border and 

 outer surface of the greater cornua of the os 

 hyoides, and from the body in their immediate 

 neighbourhood. From this double origin the 

 fibres ascend in two distinct sets. Those 

 from the greater cornua, passing up nearly 

 parallel to one another, are inserted into the 

 sides of the tongue; those from the body 

 expand as they ascend, arch forwards, and, 

 gaining the side of the tongue at a point su- 

 perior and anterior to the other, pass forward 

 along the border of the tongue, and unite with 



Jthe styloglossus to form the lateral lingual. 

 These two portions are separated below by a 

 cellular interval ; and above a few fibres of 

 the styloglossus pass in between them. Al- 

 binus has described these as three distinct 

 muscles : one, the cerato-glossus, arising from 

 the greater cornua ; another, the basio-glossits, 

 from the body : and a third, intermediate, the 

 choiidro-gtossus, taking its origin from the 

 lesser cornua. Relations : The external 

 relations of this muscle are, from above 

 downwards, with the suomaxillary gland, the 

 hypoglossal nerve, the mylohyoid, stylo- 

 hyoid, and digastric muscles ; internally, it 

 covers the glosso-pharyngeal nerve, the middle 



constrictor of the pharynx, the lingual ar- 

 tery, the stylohyoid ligament, the geniohyo- 

 glossus, and, at its attachment to the tongue, 

 the inferior lingualis, which separates it from 

 the last mentioned. Bichat erroneously states 

 that the lingual artery ordinarily passes be- 

 tween its two origins. Action : To depress 

 the sides of the tongue and render its dorsuin 

 convex ; to retract the tongue and draw it 

 downwards. It is more frequently associated 

 with other muscles than isolated in its action ; 

 and accordingly as it acts alone or together 

 with other muscles, either as concurring with 

 them or antagonising them, so its actions 

 vary. 



The genioglossus, the largest of all the mus- 

 cles of the tongue, which it connects to the 

 lower jaw, is of a radiated or fan-shape, and is 

 placed vertically in immediate contact with its 

 fellow of the opposite side. It arises from 

 the superior genial tubercle of the lower jaw 

 by a tendinous tuft from which the muscular 

 fibres radiate to their different destinations. 

 The most anterior, the shortest, forming the 

 anterior free margin of the muscle, pass up- 

 wards and forwards to the tongue, having 

 reached the under surface of which, they are 

 continued, according to Cruveilhier, on that 

 surface to the tip ; but in all the specimens 

 that I have examined they appeared to con- 

 tinue an oblique course to the dorsum. The 

 succeeding fibres pass more and more back- 

 wards, and having reached the inferior surface 

 of the tongue, are directed vertically to the 

 dorsum, into the middle line of the whole of 

 which they are inserted, from apex to base. 

 The two muscles may be separated up to the 

 point of their immergence into the tongue, 

 but beyond that line their separation is no 

 longer possible ; for, having entered the 

 tongue, they come into relation with the 

 transverse intrinsic fibres, which they cut at 

 right angles, and interlacing with which they 

 pass to the cutis of the dorsum, forming 

 part of the vertical intrinsic muscle, from 

 the rest of which they are not to be dis- 

 tinguished except by their mesial situation. 

 The fibres do not curve outwards, as sup- 

 posed by Marjolin, to form part of the 

 transverse lingual ; nor do they expand at 

 all at their insertion, as stated by Cru- 

 veilhier ; there is no disposition to lateral 

 divergence in any part of their course ; 

 on the contrary, their direction is rather 

 upwards and inwards throughout, and their 

 insertion extremely narrow a mere line 

 as it might be imagined it would be, when 

 its great longitudinal extent is remembered. 

 The longitudinal furrow is, I think, mainly 

 produced by the traction of this muscle in the 

 median line. The most inferior fibres pass 

 backwards and downwards, and are inserted 

 into the hyoglossal ligament. Some of the 

 fibres immediately above pass backwards, ac- 

 cording to some authors, to the sides of the 

 pharynx, where, uniting with the middle con- 

 strictor, they form the genio-pharyngiens of 

 Winslow. Relations: Internally with its fellow, 

 being separated merely by areolar tissue con- 



