SUBMAXILLARY REGION 



191 



inner side of the mandible ; then, identify the various muscles. 

 The hyoglossus, a portion of which was previously visible 

 behind the mylo-hyoid, is fully exposed. It is a quadrangular 

 sheet of fleshy fibres which extends from the hyoid bone to 

 the side of the tongue. Mark its position, because all the 

 structures in the region now under consideration have a more 

 or less intimate relationship to it. Thus, posterior and also 

 superficial to its upper part, the stylo-glossus muscle will be 

 recognised, whilst anterior to it are the genio-glossus and the 



M. styloglossus 



M. stylopharyngeus 

 Glosso-pharyngeal 

 nerve 



Deep part of submaxillary gland pulled backwards 

 / Submaxillary ganglion 



Submaxillary duct (Wharton's) 



Cut edge of mucous membrane 

 .Sublingual gland 



Sublingual artery 



Genio- 

 glossus 



M. geniohyoideus 



Lingual artery 

 Middle constrictor 



Lingual artery 



Hypoglossal nerve 

 v Supra-hyoid artery 



FIG. 70. Dissection of Submaxillary Region. 



genio-hyoid. The genio-hyoid muscle occupies the antero- 

 inferior part of the region, whilst the anterior part of the 

 genio-glossus is seen in the interval between the genio-hyoid 

 and the hyoglossus. Upon the surface of the hyoglossus, the 

 lingual and hypoglossal nerves, the connecting loop between 

 them, the deep portion of the submaxillary gland, with the 

 submaxillary duct, and the submaxillary ganglion, are to be 

 dissected. The lingual nerve occupies the highest level, and 

 passes forwards upon the muscle, near its insertion into the 

 tongue. The hypoglossal nerve, with its vena comitans and the 

 lingual vein, crosses the muscle close to the hyoid bone, 



