SECTION I 

 INTRODUCTION 



ANATOMY means really the study of the body, its different 

 parts and their functions, comprising histology, physiology, and 

 many other sciences ; but the generally accepted definition is, 

 that the science of anatomy is the study of the body as far 

 as it can be done by dissection and the naked eye. It is 

 necessary, therefore, to have certain well-defined terms for the 

 purposes of description ; it is always assumed that the body is 

 in the erect position with the arms by the sides, the palms 

 turned forwards and the thumbs outward. 



Sections are generally taken through the three following 

 planes : 



1. Transverse, or horizontal plane. 



2. Sagittal a vertical plane in the antero -posterior direction. 



3. Frontal a vertical plane at right angles to the sagittal. 



The Mesial Plane is the sagittal one that divides the body 

 in two halves, and is represented in front by the anterior 

 median line, and behind by the posterior median line : the two 

 halves are supposed to be symmetrical ; but like all things of 

 Nature's manufacture, are not rigidly so. Certain unpaired 

 organs, that are not in the middle line, also render the two 

 halves asymmetrical. 



The terms internal and external are used to express positions 

 nearer to, or farther from, the middle line respectively; the 

 terms dorsal and ventral are positions nearer the back or front 

 of the body respectively; posterior and anterior are synonymous 

 with dorsal and ventral ; superior and inferior indicate nearer the 

 head or the feet respectively. In the case of the limbs, the 



1 



