THE MEANING OF DIGESTION 



117 



Problem. Study of the digestive system of man. 

 Remove the heart and lungs from the mannikin. 



I. Locate the gullet and describe its exact position, including origin and end. 



II. Remove the intestines and locate the pancreas and the posterior end 

 of the large intestine called the rectum. 



III. Describe the connection of the pancreas and liver with the small in- 

 testine. 



IV. Compare the alimentary canal of the frog and man as to relative size 

 of organs and as to complexity in structiu-e. 



V. Make a diagram of the digestive system and label throat, gullet, 

 stomach, small intestine, large intestine, rectum, pancreas, and liver. 



The meaning of digestion. Before a cell in the brain, in the 

 tip of the toe, or any other part of the body can use the meat 

 or the vegetable 



that 



liver 





.esophagus 



IS eaten, 

 manv chansres, 

 physical and 

 chemical, must 

 take place in the 

 food. The organs 

 that are particu- 

 larly adapted for 

 carrying the food 

 particles, for pre- 

 paring it for ab- 

 sorption, and 

 making it ready 

 for use bv the 

 various bodv 

 cells, make up 

 the digestive sys- 

 tem. In the thrashing of grain, much of the useless is sepa- 

 rated from the useful parts of the cereal. So, in the digestive 



intftstine^. 



IslccSl^ei^ 



The digestive organs of the frog have been removed from the 

 body to show some of the digestive glands and the continuous ali- 

 mentary canal. The bladder is one of the excretory organs which 

 drains into the cloaca. The latter is the receptacle for materials 

 from the alimentary canal, reproductive organs, and the bladder. 



