Chap. XVI] 



SUMMARY 



319 



(2) The formation of red corpuscles during foetal life and for a 

 short period after birth. 



(3) The presence of a large amount of iron suggests that it may 

 help in the preparation of new haemoglobin, or in the preservation 

 of the iron set free by the death of the red corpuscles. The pres- 

 ence of iron was formerly considered an evidence that the red cor- 

 puscles were destroyed in the spleen, but this is not accepted at 

 the present time. 



(4) The spleen increases in size during digestion, and after diges- 

 tion is over it returns to its usual size. It is always large in well- 

 fed, and small in starved animals. This supports the belief that it 

 may be concerned in digestion or metabolism. 



(5) It is probable that the spleen is concerned in the production 

 of uric acid. Various waste products that result from the metab- 

 olism of protein are found in the spleen, and it is thought that by 

 the action of special enzymes these substances are changed to uric 

 acid. 



(6) In certain diseases, more especially typhoid and malaria, 

 a temporary enlargement takes place. Some physiologists inter- 

 pret this as an evidence that the spleen has an important protective 

 function. Phagocytosis is a normal occurrence, and in addition 

 it serves as a filter and may modify abnormal material found in 

 the blood. 



Metabolism 



SUMMARY 



■ Refers to changes that occur in food-stuffs from time of 

 absorption to elimination. 



1. Conversion of non-living material into 

 protoplasm. 



2. Oxidation. 



3. Neutralization or elimination of acids. 



4. Conversion of glucose into glycogen and 

 glycogen into glucose. 



Anabolic or constructive changes. 

 Katabolic or destructive changes. 



1. Release of chemical energy in the form 

 of heat, nervous and muscular activity. 



2. Repair and growth of tissue, 

 r Enzymes. 

 I Oxygen. 

 I Internal secretions. 



Consists of { 



Equals the 

 sum of the 



Functions 



Dependent 

 upon 



