1246 A MANUAL OF ANATOMY 



Septum Linguae. — The septum of the tongue is a fibrous partition, 

 which extends in the median Une from the tip of the organ to the 

 body of the hyoid bone. It divides the tongue into two sjmi- 

 metrical halves, and the Hngualis transversus muscle arises from it 

 on either side. 



Arteries. — These are as follows: (i) the ranine artery, which is 

 a branch of the lingual, and is situated on the inferior surface, im- 

 mediately external to the line of insertion of the genio-hyo-glossus 

 muscle. It anastomoses with its fellow beneath the tip. (2) The 

 dorsalis linguae artery, which is also a branch of the lingual. (3) The 

 tonsillar branch of the cervical portion of the facial artery. (4) The 

 palatine branch of the ascending pharyngeal artery. 



The veins pass to the internal jugular vein. 



Lymphatics. — The lymphatic vessels of the tongue are disposed in 

 four groups — apical, marginal, basal, and central. 



The apical lymphatics issue from the tip, and are two in number, 

 on either side. One passes to the submental, or suprahyoid, gland 

 of the same side; and the other passes to one of the internal chain 

 of substemo-mastoid glands, on a level with the cricoid cartilage of 

 the larynx. 



The marginal lymphatics convey Ijnnph from the anterior two- 

 thirds of the lateral border, and the marginal portion of the dorsum 

 for a similar extent. The anterior lymphatics of this set pass 

 through the mylo-hyoid muscle, and terminate in the anterior sub- 

 maxillary lymphatic glands. The posterior lymphatics of this set 

 pass to the superior deep cervical glands, and, more particularly, to 

 those situated under cover of the posterior belly of the digastric 

 muscle. The small lingual glands, which he upon the outer 

 surface of the hyo-glossus muscle, serve as gland-stations in their 

 path. 



The basal lymphatics return lymph from the posterior third of 

 the tongue, and have the same termination as the posterior marginal 

 lymphatics, just stated. 



The central lymphatics return the lymph from median part of the 

 tongue, and pass to the deep cervical glands, which extend from the 

 posterior belly of the digastric muscle to the level of the cricoid 

 cartilage of the larynx. 



Nerves. — The sensory nerves are: (i) the lingual branch of the 

 inferior maxillary division of the fifth cranial nerve, which is dis- 

 tributed to the mucous membrane over the anterior two-thirds of 

 the tongue, including the conical and fungiform papillce, upon 

 which it confers common sensibility ; (2) the chorda tympani 

 nerve, w'hich accompanies the lingual nerve to the anterior two- 

 thirds of the tongue, of which it is usually regarded as the nerve 

 of special sense; (3) the lingual branch of the glosso-pharyngeal 

 nerve. Which is distributed to the mucous membrane of the posterior 

 third and to the circumvallate papillce, of Which it is the nerve of 

 special sense; (4) the internal branch of the superior laryngeal 

 nerve, which furnishes a few twigs to the mucous membrane of the 



