LINGUAL REGION. 



261 



The difference in the direction of the fibres of this muscle, and their separate 

 origin from different segments of the hyoid bone, led Albinus and other anato- 

 mists to describe it as three muscles, under the names of the Basio-glossus, the 

 Cerato-glossus, and the Chondro-glossus. 



Relations. By its external surface, with the Digastric, the Stylo-hyoid, Stylo- 

 glossus, and Mylo-hyoid muscles, the gustatory and hypoglossal nerves, Wharton's 

 duct, and the sublingual gland. By its deep surface, with the Genio-hyo-glossus, 

 Lingualis, and the Middle constrictor, the lingual vessels, and the glosso-pharyn- 

 geal nerve. 



The Lingualis is a longitudinal band of muscular fibres, situated on the under 

 surface of the tongue, lying in the interval between the Hyo-glossus and the 

 Genio-hyo-glossus, and extending from the base to the apex of that organ. 

 Posteriorly, some of its fibres are lost in the base of the tongue, and others are 

 attached to the hyoid bone. It blends with the fibres of the Stylo-glossus, in front 



Fig. 155. Muscles of the Tongue. Left Side. 



of the Hyo-glossus, and is continued forwards as far as the apex of the tongue. 

 It is in relation, by its under surface, with the ranine artery. 



The Stylo-glossus, the shortest and smallest of the three styloid muscles, arises 

 from the anterior and outer side of the styloid process, near its centre, and from 

 the stylo-maxillary ligament, to which its fibres, in most cases, are attached by a 

 thin aponeurosis. Passing downwards and forwards, so as to become nearly hori- 

 zontal in its direction, it divides upon the side of the tongue into two portions : 

 one longitudinal, which is inserted along the side of the tongue, blending with 

 the fibres of ths Lingualis, in front of the Hyo-glossus ; the other, oblique, which 

 overlaps the Hyo-glossus muscle, and decussates with its fibres. 



Relations. By its external surface, from above downwards, with the parotid 

 gland, the Internal pterygoid muscle, the sublingual gland, the gustatory nerve 



