AND PIIYSIOLOGY. 



407 



tened at the end, one twenty-fourth to one twelfth of an inch 

 in diameter, with a lower uniform wall closely surrounding 

 the papilla. More nerves are distributed to the circumvallate 

 than to either of the other forms of papillae. At its lower or 

 posterior extremity the 

 tongue is attached to 

 the os hyoides, and at 

 its lower front portion 

 to the lower jaw by the 

 fraenum or bridle of 

 the tongue ; so that it 

 is left free to move ei- 

 ther backwards or for- 

 wards by the contrac- 

 tion of the appropriate 

 muscles. 



749. Blood- Vessels of this Organ —A great quantity of 

 blood-vessels are distributed to this organ, as can be seen by 

 looking at the under side of it, as well as by the free flow of 

 blood when it is wounded. 



750. Nerves of Taste —Of nerves there are no less than 

 three large branches supplied to the tongue from the cranial 

 group : the gustatory or proper nerve of taste, a branch of 

 the fifth pair which is distributed to the papillee ; the glosso- 

 pharyngeal distributed to the mucous membrane, being both 

 a nerve of motion and sensation ; and the hypoglossal distrib- 

 uted to the muscles, being preeminently a nerve of motion. 



Fig. 369. 



One of the smallest Papillae of the Tongue highly 



FUNCTIONS. 



751. Use of the Numerous Muscular Fibers in ihe 

 Tongue. — To effect the numerous movements of the tongue in 



Which kind receive the most nerves? To what is the tongue attached by its lower 

 extremity ? 749. What proportion of blood is sent to this organ ? 750. How many nerves 

 are sent to the tongue, and what are they ? 



18 



