40 STUDIES IN PHYSIOLOGY 



5. An organism, like the human body, is composed of organs, 

 each doing its special work, yet all working together 

 for the common good. Thus the hand supplies the 

 organs of digestion with food ; the organs of digestion 

 change the food into blood, some of which goes to 

 furnish the hand with the materials it needs to do its 

 work. 



THE FUNCTIONS ^CABRIED ON BY ALL PROTOPLASM 



1. Taking in of food materials. 



2. Change of food materials to protoplasm (assimilation). 



3. Taking in of oxygen (respiration). 



4. Oxidation of food materials to produce heat and other 



forms of energy. 



5. Giving off of waste materials (excretion). 



