THE LINGUAL VESSELS AND NERVE. 623 



fibres acting alone raise the hyoid bone and protrude the tongue ; 

 while the anterior retract the tip of the tongue. 



The LINGUAL ARTERY (fig. 217, /, p. 603) arises from the external Lingual 

 carotid opposite the great cornu of the hyoid bone. At first it is ascends to 

 directed forwards above the hyoid bone, and then upwards beneath 

 the hyo-glossus to the under part of the tongue (fig. 224) ; it ends at hy 

 the anterior border of that muscle in the sublingual and ranine glos 

 branches. Before it reaches the hyo-glossus, the artery forms a 

 small loop, with its convexity upwards, which is crossed by the 

 hypoglossal nerve ; and the digastric and stylo-hyoid muscles also lie 

 over the vessel, but are separated from it by the hyo-glossus. The 

 trunk rests on the middle constrictor and genio-glossus muscles. Its 

 branches are : 



a. A small hyoid branch is distributed to the muscles at the upper its branches 

 border of the hyoid bone ; it anastomoses with its fellow of the are ~ . 

 opposite side, and with the hyoid branch of the superior thyroid bone ; 

 artery of the same side. 



b. The dorsalis lingua branch arises beneath the hyo-glossus to back of 

 muscle, and ascends to supply the dorsal part of the substance of the 

 tongue and the tonsil. The fibres of the hyo-glossus must be 

 divided to see it. 



c. The subliiifjual branch springs from the final division of the to the sub- 

 artery at the edge of the hyo-glossus, and is directed outwards to the jj 

 gland of the same name. Some offsets supply the gums and the con- 

 tiguous muscles, and one continues behind the incisor teeth to join 



a similar artery from the other side. 



d. The ranine branch (fig. 224, 9 ) is the terminal part of the lingual totbesub- 

 artery, and extends forwards along the outer side of the genio-glossus tongue.^ 

 to the tip of the tongue where it ends. Muscular offsets are furnished 



to the substance of the tongue of the. same side. This artery is very 

 tortuous, and is embedded in the muscular fibres of the tongue. 



The lingual arttry is accompanied by two small vence comites, but Lingual 

 the largest vein of the tongue is the ranine, which lies external to ^ e 

 the artery of the same name, and, after being joined by subling'ual 

 branches, passes backwards over the hyo-glossus muscle with the 

 hypoglossal nerve. These veins end in the internal jugular. 



The LINGUAL NERVE (fig. 224, ') has been followed in the pterygo- Lingual 

 maxillary region to its passage between the ramus of the lower jaw nerve 

 and the internal pterygoid muscle (p. 618). In the submaxillary region 

 the nerve is inclined inwards to the side of the tongue, across the along side of 

 mucous membrane of the mouth and the origin of the superior con- ton s ue 

 strictor muscle, and above the deep part of the submaxillary gland. 

 Lastly it is directed forwards below the Whartonian duct, and along 

 the side of the tongue to the apex. Branches are furnished to the gives 

 surrounding parts, thus : 



Two or more offsets connect it with the submaxillary ganglion, toth ? 

 near the gland of that name. 



Further forwards one or more branches descend on the hyo-glossus to twelfth 

 to unite in a loop with twigs of the hypoglossal nerve. 



