THE STRUCTURE AND ACTIVITIES OF MAMMALS 403 



(upper portion in man) contains the heart and lungs. The 



posterior cavity is filled with the abdominal viscera (Fig. 273). 



Digestion. — The digestive system is similar to that of other 



vertebrates in general structure, consisting of an alimentary 



nasal cavity 

 palate 

 tongue 



opening of bile 



and pancreatic ducts 



small intestine 



^ J- passage from nose to throat 



W 



_ cavity of mouth 



hLs— { throat cavity 



v-'X. 



^mJv — opening of windpipe 



\ ^ 



pylorus 



„^ T fj^^vla--- pancreatic duct 



appendix' 



Fig. 274. — Parts of the alimentary canal of man. (From Peabody and Hunt.) 



canal and the glands connected with it (Fig. 274). The alimen- 

 tary canal begins with the mouth cavity in which are the 

 tongue and teeth, then follow in succession the oesophagus, 

 stomach, small intestine, large intestine, and rectum. The 



