594 THE VASCULAR SYSTEMS 



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

 space as the superior thyroid artery, resting upon the Middle constrictor of the pharynx, and 

 covered by the Platysma and fascia of the neck. Its second, or curved, portion also lies upon the 

 Middle constrictor, being covered at first by the tendon of the Digastric and the Stylohyoid 

 muscle, and afterward by the Hyoglossus, the latter muscle separating it from the hypoglossal 

 nerve. Its third, or horizontal, portion lies between the Hyoglossus and Geniohyoglossus 

 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 mem- 

 brane, and rests on the Lingualis on the outer side of the Geniohyoglossus. The hypoglossal 

 nerve crosses the lingual artery, and then becomes separated from it, in the second part of its 

 course, by the Hyoglossus muscle. 



Branches. The branches of the lingual artery are the 



Suprahyoid. Sublingual. 



Dorsalis Linguae. Ranine. 



The suprahyoid branch (ramus hyoideus) 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 (ramus dorsalis linguae) (Fig. 496) arises from the lingual 

 artery beneath the Hyoglossus muscle; it ascends to the back of the dorsum of 

 the tongue, and supplies the mucous membrane, the tonsil, soft palate, and 

 epiglottis, anastomosing with its fellow from the opposite side. This artery is 

 frequently represented by two or three small branches. 



The sublingual (a. sublingualis), which may be described as a branch of bifur- 

 cation of the lingual artery, arises at the anterior margin of the Hyoglossus muscle, 

 and runs forward between the Geniohyoglossus and the sublingual gland. It 

 supplies the substance of the gland, giving branches to the Mylohyoid and neigh- 

 boring muscles, the mucous membrane of the mouth and gums. One branch runs 

 behind the alveolar process of the mandible in the substance of the gum to anas- 

 tomose with a similar artery from the other side. 



The ranine, or deep lingual (a. profunda linguae), may be regarded as the other 

 branch of bifurcation. It is usually described as the continuation of the lingual 

 artery; it runs along the under surface of the tongue, resting on the Inferior lin- 

 gualis, and covered by the mucous membrane of the mouth; it lies on the outer side 

 of the Geniohyoglossus, accompanied by the lingual nerve. On arriving at the 

 tip of the tongue it is said to anastomose with the artery of the opposite side, but 

 this is denied by Hyrtl. In the mouth these vessels are placed one on either side 

 of the frenum. 



Applied Anatomy. The lingual artery may be divided near its origin in cases of cut throat, 

 a complication that not infrequently happens in this class of wounds; or severe hemorrhage 

 which cannot be restrained by ordinary means may ensue from a wound or deep ulcer of the 

 tongue. In the former case the primary wound may be enlarged if necessary, and the bleeding 

 vessels secured. In the latter case it has been suggested that the lingual artery should be tied 

 near its origin. Ligation of the lingual artery is also occasionally practised, as a palliative 

 measure, in cases of cancer of the tongue, in order to check the progress of the disease by starving 

 the growth and it is often tied as a preliminary measure to removal of the tongue. The operation 

 is a somewhat difficult one, on account of the depth of the artery, the number of important 

 structures by which it is surrounded, the loose and yielding nature of the parts upon which it is 

 supported, and its occasional irregularity of origin. An incision is to be made in a curved direc- 

 tion from a point one finger's breadth external to the symphysis of the mandible downward to the 

 cornu of the hyoid bone, and then upward to near the angle of the mandible. Care must be taken 

 not to carry this incision too far backward, for fear of endangering the facial vein. In the first 

 incision the skin, superficial fascia, and Platysma will be divided, and the deep fascia exposed. 

 The deep fascia is then to be incised, and the submaxillary gland exposed and pulled upward by 

 retractors. A triangular space is now exposed, Lesser's triangle (Fig. 440), bounded internally 

 by the posterior border of the Mylohyoid muscle; below and externally, by the tendon of the 

 Digastric; and above, by the hypoglossal nerve. The floor of the space is formed by the 



