670 THE ARTERIES. 



and hyo-glossus muscle, where it meets the branches of the lingual and hypo- 

 glossal nerves. 



Flexuous in its course, in order to adapt itself to the elongation of the tongue, 

 the lingual artery emits a very great number of collateral branches, which escape 

 perpendicularly from the entire periphery of the vessel ; but chiefly above, below, 

 and on the inner side, to ramify in the muscles and integuments of the tongue. 



Running parallel to each other, the two lingual arteries communicate by five 

 transverse ramuscules, and join at their terminal extremity, which becomes very 

 slender. 



3. Sublingual Artery (Fig. 381, 16). — This artery has its origin at the 

 anterior extremity of the submaxillary gland, and runs forward along the external 

 surface of the mylo-hyoideus muscle, which it afterwards crosses towards the 

 posterior extremity of the sublingual gland. It then follows the inferior border 

 of this gland, sending into it numerous branches, and after giving some filaments 

 to the genio-glossus and genio-hyoideus muscles, is prolonged on the sides of 

 the fraenum linguae, where it ends by fine ramuscules in the buccal mucous 

 membrane. 



Among the branches this artery detaches before attaining the sublingual 

 gland, it is necessary to distinguish those which are destined to the mylo-hyoideus 

 muscle, some of which — the descending — are thin and irregular ; the others — 

 ascending — being long, thick, and parallel to each other. 



Sometimes this artery does not reach the sublingual gland ; it then remains, 

 for the whole of its extent, external to the mylo-hyoideus muscle, and sends its 

 terminal divisions to the vicinity of the symphysis of the inferior maxilla. In this 

 case, the gland receives a special branch from the lingual artery, a circumstance 

 which is usual in Man, in whom this artery is named the suhmental. 



4. Coronary or Inferior Labial (Fig. 381, 17). — Springing from the 

 glosso-facial artery at an acute angle, shortly before that vessel arrives at the 

 depressor labii inferioris, the inferior coronary artery passes under that muscle, 

 and following its direction, descends into the texture of the lower lip, where it 

 is mixed up with the ramifications of the mental nerve, and where it terminates 

 by forming a very fine anastomotic arch with the vessel of the opposite side. 



In its track, it gives branches to the buccinator and depressor labii inferioris 

 muscles, and to the tissues of the lower lip, to which it is chiefly destined. In 

 its passage near the mental foramen, it receives the inferior dental artery as it 

 leaves that opening. 



5. Coronary or Superior Labial Artery (Fig. 381, 18). — Smaller than 

 the preceding vessel, and often altogether rudimentary, this artery is detached 

 from the principal trunk at nearly a right angle, above the origin of the dilator 

 naris lateralis, and sometimes below that muscle. It subsequently gains the upper 

 lip, along with the infra-orbital branches of the superior maxillary nerve, by 

 passing between the levator labii superioris proprius and the dilator naris 

 lateralis ; it then terminates in forming an arch by inosculation with the palato- 

 labialis artery. 



The branches it gives off" pass to the external ala of the nose and the textures 

 of the upper lip. Some are expended in the muscles just named, and in the 

 buccinator. 



2. Maxillo-musculae Artery (Fig. 381, 21). 

 The maxillo-muscular artery is a vessel that does not appear to have its 



