HUMAN PHYSIOLOGY 



INTRODUCTION 



PHYSIOLOGY is the science of normal life. It may be 

 divided into: 



1. General Physiology, i.e. the science of the general 

 properties of life or of the character of the living substance. 



2. Special Physiology, i.e. the science of the vital 

 phenomena of individual living beings (e.g. man, animals, 

 plants), and of the single organs of the living beings. 



This manual treats of the essentials of human physiology. 

 As an introduction, a brief survey of general physiology is 

 prefixed. 



GENERAL PHYSIOLOGY 



1. METABOLISM. IRRITABILITY 



The living body contains no other elements and forces 

 than those found in the inanimate world. There is no 

 special ' ( Vital Force. ' ' The properties of life are dependent 

 upon the chemical and physical properties of the living sub- 

 stance. The composition of this substance is not known; 

 in fact, it is a question whether it is chemically an indi- 

 vidual substance or a mixture of different bodies. 



The vital processes comprise chemical and physical 

 processes the changes of matter and energy [metabolism]. 



Metabolism consists of two processes: On the one hand, 

 the living being continually splits up and, by the addition of 



