BRANCHES OF THE EXTERNAL CAROTID. 489 



The hyoid branch (supra-hyoid) 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. 288) arises from the lingual artery beneath the Hyo- 

 glossus muscle (which, in the figure, has been partly cut away, to show the 

 vessel) ; it ascends to the dorsum of the tongue, and supplies the mucous mem- 

 brane, 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, which may be described as a branch of bifurcation of the 

 lingual artery, arises at the anterior margin of the Hyo-glossus muscle, and 

 runs forward between the Genio-hyo-glossus and the sublingual gland. It 

 supplies the substance of the gland, giving branches to the Mylo-hyoid and 

 neighboring muscles, the mucous membrane of the mouth and gums. One 

 branch runs behind the alveolar process of the lower jaw in the substance of the 

 gum to anastomose with a similar artery from the other side. 



The ranine may be regarded as the other branch of bifurcation, or, as is more 

 usual, as the continuation of the lingual artery ; it runs along the under surface 

 of the tongue, resting on the Inferior lingualis, and covered by the mucous 

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

 accompanied by the lingual nerve. On arriving at the tip of the tongue it has 

 been said to anastomose with the artery of the opposite side, but this is denied 

 by Hyrtl. These vessels in the mouth are placed one on each side of the frsenum. 



Surgical Anatomy. The lingual artery maybe divided near its origin in cases of cut 

 throat, a complication that not unfrequently happens in this class of wounds ; or severe 

 haemorrhage 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. Ligature 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 sometimes tied as a preliminary measure to removal of 

 the tongue. The operation is a difficult one, on account of the depth of the artery, the number 

 of important parts 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 direction from a finger's breadth external to the symphysis of the jaw downward to the 

 cornu of the hyoid bone, and then upward to near the angle of the jaw. 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. 

 This is then to be incised and the submaxillary gland exposed and pulled upward by retractors. 

 A triangular space is now exposed, bounded internally by the posterior border of the Mylo- 

 hyoid muscle : below and externally, by the tendon of the Digastric ; and above, by the hypo- 

 glossal nerve. The floor of the space is formed by the Hyo-glossus muscle, beneath which the 

 artery lies. The fibres of this muscle are now to be cut through horizontally and the vessel 

 exposed, care being taken, while near the vessel, not to open the pharynx. 



Troublesome haemorrhage may occur in the division of the fraenum in children if the ranine 

 artery, which lies on each side of it, is wounded. The student should remember that the opera- 

 tion is always to be performed with a pair of blunt-pointed scissors, and the mucous membrane 

 only is to be divided by a very superficial cut, which, cannot endanger any vessel. The scissors, 

 also, should be directed away from the tongue. Any further liberation of the tongue which may 

 be necessary can be effected by tearing. 



The Facial Artery (Fig. 285) arises a little above the lingual, and passes 

 obliquely upward, beneath the Digastric and Stylo-hyoid muscles, and frequently 

 beneath the hypoglossal nerve ; it now runs forward under cover of the body of 

 the lower jaw, lodged in a groove on the posterior surface of the submaxillary 

 gland ; this may be called the cervical part of the arterj. It then curves upward 

 over the body of the jaw at the anterior inferior angle of the Masseter muscle ; 

 passes forward and upward across the cheek to the angle of the mouth, then up- 

 ward along the side of the nose, and terminates at the inner canthus of the eye, 

 under the name of the angular artery. This vessel, both in the neck and on the 

 face, is remarkably tortuous : in the former situation, to accommodate itself to the 

 movements of the pharynx in deglutition, and in the latter to the movements of 

 the jaw and the lips and cheeks. 



