A COMPEND 



OF 



HUMAN PHYSIOLOGY. 



Introduction. An animal organism in the living condition exhibits 

 a series of phenomena which relate to growth, movement, mentality, 

 and reproduction. During the period preceding birth, as well as dur- 

 ing the period included between birth and adult life, the individual 

 grows in size and complexity from the introduction and assimilation 

 of material from without. Throughout its life the animal exhibits a 

 series of movements, in virtue of which it not only changes the rela- 

 tion of one part of its body to another, but also changes its position 

 in space. If, in the execution of these movements, the parts are 

 directed to the overcoming of opposing forces, such as gravity, fric- 

 tion, cohesion, elasticity, etc., the animal may be said to be doing 

 work. The result of normal growth is the attainment of a physical 

 development that will enable the animal, and, more especially, man, to 

 perform the work necessitated by the nature of its environment and 

 the character of its organization. In man, and probably in lower 

 animals as well, mentality manifests itself as intellect, feeling, and 

 volition. At a definite period in the life of the animal it reproduces 

 itself, in consequence of which the species to which it belon'gs is 

 perpetuated. 



The study of the phenomena of growth, movement, mentality, and 

 reproduction constitutes the science of ANIMAL PHYSIOLOGY. But as 

 these general activities are the resultant of and dependent on the 

 special activities of the individual structures of which an animal body 

 is composed, Physiology in its more restricted "and generally accepted 

 sense is the science which investigates the actions or functions of 

 the individual organs and tissues of the body and the physical and 

 chemic conditions which underlie and determine them. 

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