THE DIGESTIVE ORGANS 



if..-) 



tongue 



bladder 



oesophagus 



stomach 



into the mouth in sufficient 

 quantities to moisten the dry 

 food and thus assist in swallow- 

 ing. The tongue is a muscular 

 organ and bears on its upper 

 surface many small fleshy pro- 

 jections called papillae (pa- 

 pil'le : Latin papilla, bud), 

 some of which are fairly large 

 and are arranged on the back 

 of the tongue in the form of 

 a V (Figure 180). 



Our power to taste sweet, 

 sour, bitter, and salt, which are 

 the four fundamental tastes in 

 man, is due mainly to certain 

 nerve cells located on the larger 



papillae. The food stimuli received by the special sensory 

 cells of the papilhe are carried to the brain by the taste 



lar$e 

 intestine 



pancreas 



small 

 intestine 



appendix 



Figure 179. — Alimentary 

 Canal of Man. 



I 

 I l 



Figure 180. — Tongue. 



Figure 181. — Taste Cells. 



The taste nerve ends among 

 these cells. 



