THE SCOPE OF ANATOMY
Anatomy is the branch of knowledge concerned with the form, disposition, and structure of the tissues and organs that comprise the body. The word, which is of Greek origin, literally means “cutting apart,” and the dissection of the dead is the traditional method used in anatomy.
However, anatomists employ a host of other techniques to supplement the knowledge of gross anatomy obtained by use of the scalpel. Details invisible to the naked eye are revealed by light and electron microscopy and constitute the subdivision known as microscopic anatomy. The discipline is also extended by the study of the stages through which the organism evolves from conception through birth, youth, and maturity to old age; this study, known as developmental anatomy, is rather broader in scope than is classic embryology, which confines its attention to the unborn. Few anatomists are now satisfied by the mere description of the body and its parts, and most seek to understand the relationships between structure and function. The study of these relationships clearly merges into physiology, biochemistry, and other life sciences; it can be described as functional anatomy, but we prefer to regard a functional approach as one that should pervade all branches rather than constitute a quasi-independent study.This book is mainly concerned with gross anatomy, which is a limitation justified by the general practice of presenting microscopic and developmental anatomy in separate courses. Nonetheless, we have allowed ourselves to draw on microscopic and developmental aspects when this has seemed helpful in promoting an understanding of gross anatomy or as a means of enlivening what would otherwise be a rather dry account.
The information obtained by dissection can be arranged and organized in two principal and complementary ways. In the first, systematic anatomy, attention is successively directed to groups of organs that are so closely related in their activities that they constitute body systems with an evident common function—the digestive system, the cardiovascular system, and so forth.
Systematic anatomy lends itself to a comparative approach; readily combines gross, microscopic, developmental, and functional aspects; and provides the basis for the study of the other medical sciences. Moreover, for the beginner, it is easier to understand than regional anatomy. It is the approach employed in Chapters 2 through 10.The alternative approach, regional anatomy, is used in the second and larger part of this book. Regional (or topographical) anatomy is directly concerned with the form and relationships of all the organs present in particular parts or regions of the body. It pays less attention to function, other than the simpler, mechanical functions, than does systematic anatomy but obtains a compensating importance from its immediate application to clinical work. Because matters of detail that may lack theoretical interest are often relevant to the clinician, it is necessary to give separate consideration to the regional anatomy of the different species. Regional anatomy is one of the foundations of clinical practice, and different aspects pursued with particular aims are sometimes known as surface, applied, surgical, and radiological anatomy—terms whose connotations overlap but hardly require definition.