THE HUMAN BODY 



CHAPTER I. 



THE GENERAL STRUCTURE AND COMPOSITION 

 OF THE HUMAN BODY. 



Definitions. The living human Body may be considered 

 from either of two aspects. Its structure may be especial- 

 ly examined, and the forms, connections and mode of 

 growth of its parts be studied, as also the resemblances or 

 differences in such respects which appear when it is com- 

 pared with other animal bodies. Or the living Body may 

 be more especially studied as an organism presenting defi- 

 nite properties and performing certain actions; and then its 

 parts will be investigated with a view to discovering what 

 duty, if any, each fulfills. The former group of studies- 

 constitutes -the science of Anatomy, and in so far as it deals- 

 with the Human Body alone, of IJuman Anatomy; while 

 the latter, the science concerned with the uses or in tech- 

 nical language the functions of each part is known as 

 Pliysiology. Closely connected with physiology is the 

 science of Hygiene, which is concerned with the conditions 

 which are favorable to the healthy action of the various 

 parts of the Body ; while the activities and structure of the 

 diseased body form the subject-matters of the sciences of 

 Pathology and Pathological Anatomy. 



Tissues and Organs. Histology. Examined merely 

 from the outside our Bodies present a considerable com- 

 plexity of structure. We easily recognize distinct parts as 

 head, neck, trunk and limbs; and in these again smaller 



