Etiology and pathogenesis

The term «etiology» is purely medical one. It appeared in ancient times. For many centuries the essence of the term has been changing. Thus, Claudius Galen used it as a synonym to «pathology», but he also considered that etiology is a sum of internal and external factors as well as pathological changes. Contemporary specialists consider that it is only a cause of a disease (microbe, virus, and trauma).

Literary «etiology» means study of the causes of the disease, thus its philosophical concept is equal to cause.

Pathogenesis is a mechanism of development of the pathological process (disease). The basis of this genesis is common biological laws of regulation of physiological processes. The mechanisms include proper physiological processes (reflex) and biochemical shifts which are the base of physiological processes. These shifts are reflected in structural transformations. In other words, pathogenesis of the process is closely connected with its histogenesis, the latter allows to conclude about functional aspect of the process. Morphological changes have definite regularities of development; they illustrate separate phases of the process (usually stereotypical and cyclic) and make the process stable. Thus, pathogenesis means not only functional (physiological, biochemical, immunological) shifts but also structural changes in definite tissues and organs. Pathogenesis also means localization of the process which is reflected in the clinical picture of the disease. Pathogenesis is connected with the etiology of the disease (its internal and external causes). Very often individuality and heredity determine the ways of interaction of the organism and the environment as well as interorgan correlations. The ability of the organs and the whole organism to rebuild the rhythm of its excitement to change its properties creates a very sophisticated mechanism. The problem of pathogenesis is very complicated. At present it is one of the most important aspects of the theory of disease. The knowledge of the

pathogenesis enables the physician to interfere the disease development. The mechanisms and reactions of pathogenesis have adaptive and compensatory character. Neural and humoral mechanisms are the most important. The primary regularity of pathogenesis is self-development, self-movement, and self-regulation. It means that once the process appeared, it develops in chain-like manner, like a chain consisting of many links which manifest themselves consequently. This regularity embraces all physiological phenomena. At present it is known as a new branch of science, cybernetics: theories, hypothesis and viewpoints about general questions of management and communication in automatic machines and living organisms.