THE PHARYNGEAL REGION. 327 



anterior fibres of the Inferior lingualis. The Inferior lingualis is a longitudinal- 

 band, situated on the under surface of the tongue, and extending from the base to 

 the apex of the organ. Behind, some of its fibres are connected with the body of 

 the hyoid bone. It lies between the Hyo-glossus and the Genio-hyo-glossus, and 

 in front of the Hyo-glossus it gets into relation with the Stylo-glossus, with the 

 fibres of which it blends. It is in relation by its under surface with the ranine 

 artery. 



Surgical Anatomy. The fibrous septum which exists between the two halves of the 

 tongue is very complete, so that the anastomosis between the two lingual arteries is not very 

 free, a fact often illustrated by injecting one-half of the tongue with colored size, while the other 

 half is left uninjected or is injected with size of a different color. 



This is a point of considerable importance in connection with removal of >ne-half of the 

 tongue for cancer, an operation which is now frequently resorted to when the disease is strictly 

 confined to one side of the tongue. If the mucous membrane is divided longitudinally exactly 

 in the middle line, the tongue can be split into halves along the median raphe without any 

 appreciable haemorrhage, and the diseased half can then be removed. 



Actions. The movements of the tongue, although numerous and complicated, 

 may be understood by carefully considering the direction of the fibres of its 

 muscles. The G-enio-hyo-glossi muscles, by means of their posterior fibres, draw 

 the base of the tongue forward, so as to protrude the apex from the mouth. The 

 anterior fibres draw the tongue back into the mouth. The whole length of these 

 two muscles, acting along the middle line of the tongue, draw it downward, so as to 

 make it concave from side to side, forming a channel along which fluids may pass 

 toward the pharynx, as in sucking. The Hyo-glossi muscles depress the tongue 

 and draw down its sides, so as to render it convex from side to side. The Stylo- 

 glossi muscles draw the tongue upward and backward. The Palato-glossi muscles 

 draw the base of the tongue upward. With regard to the intrinsic muscles, both 

 the Superior and Inferior linguales tend to shorten the tongue, but the former, in 

 addition, turn the tip and sides upward so as to render the dorsum concave, while 

 the latter pull the tip downward and cause the dorsum to become convex. The 

 Transverse lingualis narrows and elongates the tongue, and the Vertical lingualis 

 flattens and broadens it. The complex arrangement of the muscular fibres of 

 the tongue, and the various directions in which they run, give to this organ the 

 power of assuming the various forms necessary for the enunciation of the different 

 consonantal sounds ; and Dr. Macalister states that " there is reason to believe 

 that the musculature of the tongue varies in different races owing to the hereditary 

 practice and habitual use of certain motions required for enunciating the several 

 vernacular languages." 



5. Pharyngeal Region. 



Inferior constrictor. Superior constrictor. 



Middle constrictor. Stylo-pharyngeus. 



Palato-pharyngeus. j (gee 



Salpmgo-pharyngeus. j v 



Dissection (Fig. 208). In order to examine the muscles of the pharynx, cut through the 

 trachea and oesophagus just above the sternum, and draw them upward by dividing the loose 

 areolar tissue connecting the pharynx with the front of the vertebral column. The parts being 

 drawn well forward, apply the edge of the saw immediately behind the styloid processes, and 

 saw the base of the skull through from below upward. The pharynx and mouth should then 

 be stuffed with tow, in order to distend its cavity and render the muscles tense and easier of 

 dissection. 



The Inferior constrictor, the most superficial and thickest of the three con- 

 strictors, arises from the sides of the cricoid and thyroid cartilages. To the 

 cricoid cartilage it is attached in the interval between the Crico-thyroid muscle 

 in front and the ai'ticular facet for the thyroid cartilage behind. To the thyroid 

 cartilage it is attached to the oblique line on the side of the great ala, the 

 cartilaginous surface behind it, nearly as far as its posterior border, and to the 

 inferior cornu. From these attachments the fibres spread backward and inward, 

 to be inserted into the fibrous raphe in the posterior median line of the pharynx. 



