CHAPTER II 



THE STRUCTURE (ANATOMY) OF THE HUMAN 

 MECHANISM 



Anatomy is studied partly by dissection, which reveals 

 chiefly those organs which are visible to the naked eye, and 

 partly by microscopic examination, which gives a deeper in- 

 sight into the detailed arrangement of the cells and tissues 

 of which the organs of the mechanism are composed. The 

 present chapter is devoted to structures or organs shown 

 by dissection the gross anatomy of the body as distin- 

 guished from its microscopic anatomy (histology). 1 



1 Further explanation of the structure of the human machine will be 

 given as it may be needed in subsequent chapters. At this point it is of 

 the utmost importance that the student thoroughly master the general 

 relations of the more important organs one to another ; this, however, 

 is not to be done by extensive reading, and still less by memorizing verbal 

 descriptions ; the aim should rather be to acquire from figures and dia- 

 grams, or better yet from actual dissection, where that is possible, a correct 

 mental picture of the structures involved. Far more can be learned by 

 constructing drawings or diagrams from memory than by the mere memo- 

 rizing of text. The drawings may lack finish and may be at first difficult 

 to execute ; but so long as they represent the relations of the organs one 

 to another they accomplish their purpose ; beyond this point the more 

 accurately they are drawn the better. 



Moreover, drawing is a great aid to dissection. It not only fixes in the 

 memory what is seen but it compels close observation ; when one draws an 

 object he is forced to note details and relations of structure which would 

 otherwise escape observation. Nor is the freehand drawing which is re- 

 quired for our purpose so difficult as is often supposed by those who 

 have never seriously used it. Let the student attempt to reproduce an 

 object from his memory of its picture ; begin with one which is not too 

 complicated (such as the figure of the peritoneum and mesentery on 

 page 14). Where he does not know how to represent a special structure, 

 let him refer to the original, from which he may get suggestions; then 

 close the book and draw from memory ; any completed part of the work 

 may be compared with the original and possible improvements discovered. 



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