ELEMENTS OF ANATOMY, 



INTRODUCTION. 



Division of natural Bodies.- The material objects which exist in nature 

 belong to two great divisions ; those which are living or which have lived, 

 and those which neither are nor have ever been endowed with life. The 

 first division comprehends animals and plants, the other mineral sub- 

 stances. 



In a living animal or plant, changes take place, and processes are carried 

 on, which are necessary for the maintenance of its living state, or for the 

 fulfilment of the ends of its being ; these are termed its functions, and 

 certain of these functions, being common to all living beings, serve among 

 other characters to distinguish them from inert or mineral substances. 

 Such are the function of nutrition, by which living beings take extraneous 

 matter into their bodies, and convert it into their own substance, and the 

 function of generation or reproduction, by which they give rise to new 

 individuals of the same kind, and thus provide for the continuance of their 

 species after their own limited existence shall have ceased. 



But, in order that such processes may be carried on, the body of a living 

 being is constructed with a view to their accomplishment, and its several 

 parts are adapted to the performance of determinate oftices. Such a consti- 

 tution of body is termed organisation, and those natural objects which possess 

 it are named organised bodies. Animals and plants, being so constituted, 

 are organised bodies, while minerals, not possessing such a structure, are 

 inorganic. 



Object of Anatomy. The object of anatomy, in its most extended sense, 

 is to ascertain and make known the structure of organised bodies. But the 

 science is divided according to its subjects ; the investigation of the 

 structure of plants forms a distinct study under the name of Vegetable 

 Anatomy, and the anatomy of the lower animals is distinguished from that 

 of man or human anatomy under the name of Comparative Anatomy. 



Organs and Textures. On examining the structure of an organised body, 

 we find that it is made up of members or organs, through means of which 

 its functions are executed, such as the root, stem, and leaves of a plant, 

 and the heart, brain, stomach, and limbs of an animal ; and further, that 

 these organs are themselves made up of certain constituent materials named 

 tissues or textures, as the cellular, woody, and vascular tissues of the 

 vegetable, or the osseous, muscular, connective, vascular, and various 

 others, which form the animal organs. 



