PHYSIOLOGY 



Physiology is that science which treats of the actions or func- 

 tions peculiar to living organized beings during the continuance of 

 health, or normal life. 



These actions, when they occur in a disturbed or irregular man- 

 ner, constitute disease, or abnormal life; and become the subject 

 of the science of Pathology. Every living being is organized, — 

 that is, composed of different parts or organs, each of which has its 

 definite structure, by which it differs from other parts, and is capable 

 of fulfilling a certain end. The complex matter, which enters into 

 the composition of an organized being, or organism, is called or- 

 ganic matter, and is obtained by its proximate analysis. By its ulti- 

 mate analysis, this matter is resolved into its elementary principles, or 

 inorganic elements, such as constitute other objects in the universe. 



The mineral kingdom does not exhibit the same distinctness and 

 variety of structure, in the component parts of its various bodies, 

 nor is there any adaptation of these parts to separate functions ; 

 they are, therefore, called u?iorga7iized or inorganic, and are, by 

 chemical analysis, resolved into those simple elements which admit 

 of no farther subdivision. 



Organized bodies are found in one of two states or conditions, viz., 

 that of life, or death. That of life, is a state of action, or of capacity 

 for action. That of death, is one in which all vital action has 

 ceased, and to which the disintegration of the organized- body suc- 

 ceeds as a natural consequence. 



An organized body in a state of active life, exhibits certain pro- 

 cesses by which its growth and nutrition are provided for, and which 

 enable it to resist the destructive influence of surrounding agents. 

 The object of these processes, is to promote the development, and 

 to preserve the integrity of the body itself. The simplest animal or 

 vegetable, is an illustration of this remark. 



The very processes which denote vital activity, may be sometimes 

 temporarily suspended, even in fully formed animals and vegetables ; 

 and in such instances, life may be said to become dormant. Of 

 this we have an exeimple in the ordinary wheel animalcule, which, 



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