THE VERTEBRATE ANIMAL — SUBPHYLUM VERTEBRATA 



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The Digestive Enzymes and Their Functions 



*The esophagus and colon do not secrete any enzymes. 



the bile. Bile is secreted all of the time, but between meals it is stored 

 in the gall bladder and supplied in quantity at meal time. 



Besides these digestive and excretory functions the liver serves 

 in another capacity. It is a storehouse for carbohydrates which it 

 converts to glycogen (animal starch) by enzyme action. This sub- 

 stance is also stored in the voluntary muscles. It is easily recon- 

 verted to dextrose for ready oxidation. Most of the protein by- 

 product iirea (and uric acid in some forms) is formed in the liver 

 and carried by the blood to the kidneys for excretion. 



