LINGUAL AND FACIAL ARTERIES. 285 



The Hyoid branch passes forwards beneath the thyro-hyoideus, and is 

 distributed to the depressor muscles of the os hyoides near their insertion. 



The Superior laryngeal pierces the thyro-hyoidean membrane, in com- 

 pany with the superior laryngeal nerve, and supplies the mucous mem- 

 brane and muscles of the larynx, sending a branch upwards to the 

 epiglottis. 



The Inferior laryngeal is a small branch which crosses the crico-thyroi- 

 dean membrane along the lower border of the thyroid cartilage. It sends 

 branches through the membrane, to supply the mucous lining of the larynx, 

 and inosculates with its fellow of the opposite side. 



The Muscular branches are distributed to the depressor muscles of the 

 os hyoides and larynx. One of these branches crosses the sheath of the 

 common carotid to the under surface of the sterno-rnastoid muscle. 



2. The LINGUAL ARTERY ascends obliquely from its origin, it then 

 passes forwards parallel with the great cornu of the os hyoides ; thirdly, it 

 ascends to the under surface of the tongue ; and, fourthly, runs forward 

 in a serpentine direction to its tip (under the name of the ranine artery], 

 where it terminates by inosculating with its fellow of the opposite side. 



Relations. The first part of its course rests upon the middle constrictor 

 muscle of the pharynx, being covered in by the tendon of the digastricus 

 and the stylo-hyoid muscle ; the second is situated between the middle 

 constrictor and hyo-glossus muscle, the latter separating it from the hypo- 

 glossal nerve ; in the third part of its course it lies between the hyo-glossus 

 and genio-hyo-glossus ; and in the fourth (ranine) rests upon the lingualis 

 to the tip of the tongue. 



Branches. Hyoid, 



Dorsalis linguae, 

 Sublingual. 



The Hyoid branch runs along the upper border of the os hyoides, and 

 is distributed to the elevator muscles of the os hyoides near their origin, 

 inosculating with its fellow of the opposite side. 



The Dorsalis linguae ascends along the posterior border of the hyo- 

 glossus muscle to the dorsum of the tongue, and is distributed to the 

 tongue, the fauces, and epiglottis, anastomosing with its fellow of the op- 

 posite side. 



The Sublingual branch, sometimes considered as a branch of bifurca- 

 tion of the lingual, runs along the anterior border of the hyo-glossus, and 

 is distributed to the Sublingual gland and to the muscles of the tongue. 

 It is situated between the mylo-hyoideus and genio-hyo-glossus, generally 

 accompanies Wharton's duct for a part of its course, and sends a branch 

 to the frsenum linguae. It is the latter branch which affords the consider 

 able haemorrhage which sometimes follows the operation of snipping the 

 frsenum in children. 



3. FACIAL ARTERY. The Facial artery arises a little above the greai 

 cornu of the os hyoides, and descends obliquely to the submaxillary gland, 

 in which it lies embedded. It then curves around the body of the lower 

 jaw, close to the anterior inferior angle of the masseter muscle, ascends 

 to the angle of the mouth, and thence to the angle of the eye, where it is 

 named the angular artery. The facial artery is tortuous in its course 



