CHAPTER II 



DEFINITIONS. — CAVITIES OF THE BODY 



DEFINITIONS 



Before taking up the subjects of anatomy and physiology in 

 detail, it is well first of all to consider the definitions of these 

 terms as follows : — 



Anatomy refers to the structure of the body. 



Physiology refers to the functions of the different parts of the 

 body, in a state of health. 



Anatomy teaches us what organs a plant or animal has, and how 

 they are arranged with reference to one another. Physiology 

 teaches us the uses to which these organs are put. Anatomy 

 shows what an organ is ; physiology shows what an organ does. 

 Anatomy may be, and usually is, studied upon the dead crea- 

 ture ; physiology can be studied only upon the living creature. 



Anatomy is sometimes divided into the following branches : — 



Osteology is the anatomy of the bones. 

 Syndesmology is the anatomy of the joints. 

 Myology is the anatomy of the muscles. 

 Angiology is the anatomy of the vessels. 

 Neurology is the anatomj'^ of the nerves. 

 Splanchnology is the anatomy of tlic internal viscera. 

 Adenology is the anatomy of the glands. 

 Dermatology is the anatomy of the skin. 

 Genesiology is the anatomy of the generative organs. 



The Anatomical Position. — In describing the body, anatomists 

 always consider it as being in the erect position, with the face 

 toward the observer, the arms hanging at the sides, and the palms 

 of tlie hands turned forward. 



Surfaces of the Body. — When the body is in the anatomical 

 position, the front, or surface facing the observer, is named the 

 anterior or ventral surface. (See Fig. 1.) The back, or surface 

 directed away from the observer, is named the posterior or dorsal 

 surface. (See Fig. 2.) 



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