8o 



PRACTICAL ANATOMY. 



examining your work, has exposed the anterior belly of the digastric muscle, 

 the hyo-glossus muscle, the mylo-hyoid muscle, the branches of the external 

 carotid artery, the hypoglossal nerve, and, to some extent, the muscles and liga- 

 ments attached to the styloid process of the temporal bone. To dissect the 

 tongue and mouth you proceed as follows : Retract the chin, saw through the sym- 

 physis menti ; then, with a sharp knife, cut through the center of the tongue from 

 tip to hyoid bone. You will then see, separated by connective tissue areas, the 

 mylo-hyoid, the genio-hyoid, and the genio-hyo-glossus muscles as in figure 44. 

 24. The boundary between the mouth and the pharynx. Examine a patient 

 and you will see the soft palate hanging down between the mouth and pharynx. 



Stylo-glOBSua 



DORSUM OF TONGUE 



Genio-hyo-glossus 

 Genio-hyoid 



STYLOID PROCESS 

 Stylo-hyoid 



POSTERIOR PORTION 

 OF TONGUE 



GREATER CORNU OF HYOID BONE 



Stylo-phary ngeun 



CARTILAGO TRITICEA 



Thyro-hyoid 

 membrane 



THYROID CARTILAGE 



Median portion of 

 crico-thyroid 

 membrane 



CRICOID CARTILAGE 

 FIRST RING OF TRACHU 



FIG. 44. SIDE VIEW OK THE TONGUE, WITH ITS Mt SCI.KS. 



The passage between the two cavities, bounded by the tongue, anterior pillar of 

 fauces, and uvula is called the isthmus of the fauces. The student should early 

 become familiar with the soft palate, as its function is complex and of a very 

 interesting and practical nature. 



Study the movements of the hyoid bone : 



1. Elevated by the stylo-hyoid and digastric behind and the genio-hyoid 

 and mylo-hyoid in front. These muscles are clearly antagonistic. The former 

 are supplied by the seventh, the latter by the twelfth and fifth nerves. 



2. Forward. The genio-hyoid, when not antagonized by the stylo-hyoid, 

 pulls the tongue forward. 



