DESCRIPTIVE AND APPLIED ANATOMY. 



INTRODUCTION. 



A X ATOMY (dv, apart, and re/wci), I cut) is the name given to that division 

 -.!_ of natural science which deals with the structure or organization of living 

 things. Human anatomy is that division of general anatomy which applies to the 

 structure of man, bearing in mind the fact that man is distinguished as a sepa- 

 rate genus among primate mammals, an order of vertebrates. 



Man, as a vertebrate, possesses an internal skeleton with a median longitudinal 

 axis, which is divided transversely into segments called vertebrae. This vertebral 

 axis (spinal column) in the habitually erect position of the human body is sup- 

 ported by the pelvic limbs, and is surmounted by the skull. The pelvic limbs 

 serve the purposes of progression, while the pectoral limbs are adapted as organs 

 of prehension; a distinction common to nearly all primates is the possession of 

 an opposable first digit or thumb. The possession of milk glands, rudimentary 

 in the male, but well developed and important in the female, relegates the human 

 species to the class of mammals. 



The present work is an account of the various parts and organs of the human 

 body, being descriptive of their characteristics as revealed by dissection, and, 

 with a view toward practical application, certain parts or regions of the body 

 are examined in their entirety. These two methods of studying anatomy are 

 conventionally termed descriptive anatomy and applied or topographic anatomy. 

 Embryology deals with the origin and development of the body and its organs. 

 Histology deals with the minute structure of the tissues and organs as revealed 

 by the microscope. In the present work only brief accounts of the embryology 

 and histology of the organs are interpolated in their proper places; the minute 

 details must be sought for in special works upon these subjects. 



The systematic consideration of the parts of the human body requires a foreword 

 as to the descriptive terms, nomenclature, and classification employed in anatomy. 



The descriptive terms are names indicative of position and direction. Despite 

 the structural homologies discernible among vertebrates in general, there are 

 wide differences regarding the natural attitude or position habitually assumed, so 

 that whatever is situated " in front" in the erect man is " below" in the quadrupedal 

 animal. The use of terms like anterior, posterior, superior, inferior, in front of, 

 beneath, has given rise to great ambiguity and confusion whenever applied at one 

 and the same time to homologous parts in man and other vertebrates. 



It is essential that the names used in designating structural parts shall be so 

 definite that each of the terms shall have but one signification. The study of 

 anatomy has been made unnecessarily difficult by a multiplicity of synonyms and 

 compound names, when single words would answer all requirements. Further- 

 more, many of the terms even now in general use are not equally applicable to 

 lower animals and man, a condition which constitutes a great hindrance to ana- 

 tomic progress. Various reforms have been proposed, chief of which has been 

 that of a commission of the German Anatomic Society, which, in 1895, formulated 

 a list of terms, the Basle Nomina Anatomica (BXA), which is unfortunately 



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