SUPERIOR THYROID; LINGUAL. 3T3 



The superior laryngeal, larger than either of the preceding, accompanies the 

 superior laryngeal nerve, beneath the Thyro-hyoid muscle ; it pierces the thyro- 

 hyoid membrane, and supplies the muscles, mucous membrane, and glands of the 

 larynx and epiglottis, anastomosing with the branch from the opposite side. 



The crico-thyroid (inferior laryngeal) is a small branch which runs transversely 

 across the crico-thyroid membrane, communicating with the artery of the oppo- 

 site side. The position of this vessel should be remembered, as it may prove the 

 source of troublesome hemorrhage during the operation of laryngotomy. 



Surgical Anatomy. The superior thyroid, or some of its branches, is occasionally divided 

 in cases of cut-throat, giving rise to considerable hemorrhage. In such cases, the artery should 

 be secured, the wound being enlarged for that purpose, if necessary. The operation may be 

 easily performed, the position of the artery being very superficial, and the only structures of 

 importance covering it being a few small veins. The operation of tying the superior thyroid 

 artery, in bronchocele, has been performed in numerous instances with partial or temporary suc- 

 cess. When, however, the collateral circulation between this vessel and the artery of the oppo- 

 site side, and the inferior thyroid, is completely re-established, the tumor usually regains its 

 former size. 



The LINGUAL ARTERY (fig. 212) arises from the external carotid between the 

 superior thyroid and facial ; it runs obliquely upwards and inwards to the great 

 cornu of the hyoid bone, then passes horizontally forwards parallel with the great 

 cornu, and, ascending perpendicularly to the under surface of the tongue, turns 

 forwards on its under surface as far as the tip of that organ, under the name of 

 the ranine artery. 



Relations. Its first, or oblique portion, is superficial, being contained in the 

 triangular intermuscular space already described, resting upon the Middle con- 

 strictor of the pharynx, and covered by the Platysma and fascia of the neck. Its 

 second or horizontal portion also lies upon the Middle constrictor, being covered 

 at first by the tendon of the Digastric, and the Stylo-hyoid muscle, and afterwards 

 by the Hyo-glossus, the latter muscle separating it from the hypoglossal nerve. 

 Its third or ascending portion lies between the Hyo-glossus and Genio-hyo-glossus 

 muscles. The fourth or terminal part, under the name of the ranine, runs along 

 the under surface of the tongue to its tip ; it is very superficial, being covered 

 only by the mucous membrane, and rests on the Lingualis on the outer side of 

 the Genio-hyo-glossus. The hypoglossal nerve lies nearly parallel with the lingual 

 artery, separated from it, in the second part of its course, by the Hyo-glossus 

 muscle. 



The branches of the lingual artery are the 



Hyoid. Sublingual. 



Dorsalis linguae. Ranine. 



The hyoid branch runs along the upper border of the hyoid bone, supplying 

 the muscles attached to it, and anastomosing with its fellow of the opposite 

 side. 



The dorsalis linguae (fig. 212) arises from the lingual artery beneath the Hyo- 

 glossus muscle ; ascending to the dorsum of the tongue, it supplies its mucous 

 membrane, the tonsil, soft palate, and epiglottis, and anastomoses with its fellow 

 from the opposite side. 



The sublingual, a branch of bifurcation of the lingual artery, arises at the ante- 

 rior margin of the Hyo-glossus muscle, and, running forwards and outwards 

 beneath the Mylo-hyoid to the sublingual gland, supplies its substance, giving 

 branches to the Mylo-hyoid and neighboring muscles, the mucous membrane of 

 the mouth and gums. 



The ranine may be regarded as the continuation of the lingual artery ; it runs 

 along the under surface of the tongue, resting on the Lingualis, and covered by 

 the mucous membrane of the mouth ; it lies on the outer side of the Genio-hyo- 

 glossus, and is covered by the Hyo-glossus and Stylo-glossus, accompanied by 

 the gustatory nerve. On arriving at the tip of the tongue, it anastomoses with 



