CHAPTER LXVIII 

 TASTE AND SMELL 



Taste The Receptor Mechanism. The taste buds probably form 

 the receptor mechanism for the sensation of taste, for the sense of 

 taste is absent from those parts of the tongue where these organs do 

 not exist, and is most acute in the regions where they are most abun- 

 dant. Further, section of the glosso-pharyngeal nerve, the nerve of 

 taste, leads to a degeneration of the sensory cells in these buds. 



The taste buds are found in many of the fungiform and in all the 

 circumvallate papillae of the tongue; to a certain extent also on the 



A 



i<'io. 331. MICROSCOPIC VIEW OF SECTION THROUGH CIRCUMVALI.ATK PAPILL.+:. 

 A, epithelial layer; B, taste buds; D, gland; E, subepithelial layer; G, muscle. 



soft palate and the surface of the epiglottis. They are best seen in 

 the circumvallate papillae. These are eight to fifteen in number, and 

 form at the base of the tongue a V, with the apex backwards: it is 

 calculated that there are more than 30,000 taste buds in this region 

 in the ox. They are far more numerous in the embryo at the sixth 

 to the seventh month than in the adult. Many of them subsequently 

 become infiltrated with leucocytes and destroyed. The fungiform 

 (fungus-like) and filiform (rod-like) papillae of the tongue are concerned 

 in the sensations of touch, temperature, and pain. 



The taste buds are minute oval bodies embedded in the epithelial 

 layer, and communicating with the surface by a funnel-shaped opening 



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