TASTE AND SMELL 



95 



Fig. 54. Section of circumvallate 

 papilla. 



which give a marked roughness to the surface. On the 

 front and sides of the tongue the papillae are generally 

 long and slender, and are 

 therefore called filiform 

 papillce. Others with 

 broad, spreading, mush- Taste B 

 room-shaped tops are scat- 

 tered among the filiform 

 papillae and are called fun- 

 giform papillce. A third 

 variety, the largest of all, is 

 the circumvallate papillce (Fig. 54). These last are only 

 eight or ten in number, and are seen at the back of a man's 

 tongue, in two rows converging to a point backward. 



122. Taste Buds. In the walls of the circumvallate and 

 in some, at least, of the fungiform papillae the end organs 

 for taste have been found. These 

 consist of a number of overlapping 

 epithelial cells, like the leaves of a 

 bud (Fig. 55). The innermost core 

 of the bud is a number of slender, 

 closely packed cells terminating in 

 fine, stiff spikes which project at the 

 surface of the bud. These are the 



Jc Iff* 00 



A isolated taste bud, from taste ce ^ s and are tne essential part 

 whose upper free end o f the taste buds. Around these 



project the ends of the ,, ., ,., 



taste cells. CQLls the nerve filaments from cer- 



B supporting or protect- ta j n branches of the ninth pair of 



ing cell. ,0.1 7 7 



C taste cell. cranial nerves (the glossopharyn- 



geal) end in brushlike expansions. 



Branches from the fifth cranial nerve (the triyeminaT) 

 are also distributed to the tongue, and are believed by 

 many physiologists to be concerned in taste. 



Taste Cells 



upporting 

 Cells 



