Organopathology

ORGANOPATHOLOGY, a branch of pathology that studies pathological changes in the structure (special pathological anatomy) and function (special pathological physiology) of organs. In special pathological anatomy, pathological changes characteristic of individual organs are usually considered systematically, without indicating the connection of the latter with one another and without describing the resulting general picture of lesions characteristic of one or another clinical form of disease. Such an approach has been accepted since the time of Rokitansky and Virchow and is carried out in the vast majority of textbooks on pathological anatomy; however, from the point of view of medical education and the current state of pathology, it is far from sufficient and hardly expedient: for a physician who is not a specialist pathologist, it is necessary to have a clear and coherent idea of the entire picture of pathological changes characteristic of individual clinical forms of disease, which is much more important for understanding clinical data and pathogenesis than fragmented knowledge of the pathological morphology of individual organs. In some modern manuals on pathological anatomy, the basis of the presentation is no longer the changes in individual organs, but individual diseases, with a complete picture of the morphological changes characteristic of them throughout the entire organism being provided. The teaching of special pathological anatomy is also gradually being reorganized in a similar direction. In special pathological physiology, since the time of the classical lectures of Cohnheim, the material is usually presented not strictly by organs, but rather by physiological systems (e.g., the system of circulatory organs, digestion, etc.). There is still no independent presentation of the pathological physiology of individual clinical forms of disease; the corresponding information is mostly interspersed incidentally in clinical courses. In a broader sense, organopathology represents a trend of scientific thought in medicine that seeks to link a pathological process or disease with a change in the structure or function of specific organs. Such a trend ("organicism") arose historically as a result of major advances in normal anatomy and physiology, after it became possible to link individual life manifestations of the organism with the structure and function of its specific organs (Vesalius, Harvey, Malpighi, and others). Morgagni must be considered the founder of organopathology; in his book "De sedibus et causis morborum per anatomen indigatis" (1761), he first pointed out the connection between morbid phenomena and a specific anatomical substrate—pathologically altered organs. The latter are the "sedes morbi"; diseases are, as it were, localized in them. This doctrine was, in its time, a major step forward on the path to scientific medicine, especially in comparison with the purely speculative systems that prevailed at that time. In later times, the connection of diseases with pathological changes in organs was refined by Rokitansky and especially by Virchow. However, Rokitansky attributed secondary importance to organ changes, ascribing the essence of diseases to changes in the blood, whereas Virchow considered changes in cells to be the primary cause of diseases. During the exclusive dominance of Virchow's cellular pathology, organopathology acquired particularly great importance, as it received new reinforcement from the results of microscopic study of affected organs from the point of view of changes in the cells composing them. Such organicism in pathology persisted thereafter, although the pathophysiological trend, which had been gradually strengthening since the time of Cohnheim, proceeded to a significant extent from other basic premises, studying general disturbances in the function of entire physiological systems of the organism. The doctrine of constitution, which revived in the 1890s as a doctrine of the general properties of the entire organism having significance in pathogenesis and etiology, contradicted strict organicism to a significant degree; attempts were made to reconcile this doctrine with the organicism that prevailed at that time, based on the idea that each organ has its own special constitution, and the constitution of the entire organism is merely the sum of the constitutions of its individual organs (Martius). Modern pathology is moving further and further away from such extreme organicism, recognizing that in every disease, the entire organism participates to a greater or lesser extent. The constitution of the whole organism is by no means a simple sum of the individual characteristics of its organs, but represents a new qualitative category subject to its own laws (Krehl). The latter manifest themselves primarily in the correlative relationships of organs with one another and in the peculiarity of the reactions of the entire organism to stimuli from the environment. Likewise, a disease of the whole organism is not merely a simple sum of the pathological life manifestations of individual affected organs, but is, in addition, a disorder of their coordination and a disturbance of the normal relationships of the entire organism with the environment. The identification of a large group of systemic diseases has already significantly undermined the doctrine of the organ localization of diseases. The pathogenetic essence of many diseases has been considered from the point of view of the involvement of entire tissue systems that react identically to pathological stimuli, although they do not constitute a single organ. Such systematicity of lesions is acquiring ever greater importance in pathology, because with this concept, the pathogenetic features of many, in particular infectious, diseases (e.g., typhoid fever, typhus, etc.) become understandable. The modern doctrine of the reticulo-endothelial system, which in its basic concepts sharply departs from the principle of the organism, is also a vivid illustration of how the essence of many pathological processes can be understood only by proceeding from the idea of the presence in the organism of identically reacting functional systems. Finally, the recently advanced concept of intermediate substances as substances possessing basic vital properties and the capacity for pathological reactions also sharply contradicts the principles of strict organicism; the essence of many diseases can be understood only from the point of view of systemic involvement of these substances throughout the organism. The neohumoral concepts of the modern doctrine of infection and immunity contradict the principles of organicism to an even greater extent. The basic tenets of this doctrine are of paramount importance for understanding pathological changes in infectious diseases; in these, lesions of various organs and systems, as well as local tissue reactions in general, are in close dependence, during their onset and course, on the general immunobiological, resp. allergic, state of the organism (e.g., inflammatory processes that proceed differently in an allergic organism than in a normal one). With the clarification of the exceptionally important significance of neuro-humoral connections in the organism, the possibility of considering many pathological processes as reactions of the entire organism and its functional systems has acquired further justification. Modern endocrinology has provided particularly clear examples in this regard, having clarified the existence of hormonal connections between distant organs and allowing many pathological processes to be viewed from the point of view of the disturbance of the latter. The doctrine of the autonomic nervous system has played the same role, allowing the center of gravity in the interpretation of the pathogenesis of certain pathological processes to be shifted from the dysfunction of specific organs to disturbances of the autonomic impulses regulating their activity. The doctrine of avitaminoses has likewise shown that the involvement of individual organs in them must be viewed only as secondary local manifestations of a general pathological state of the organism that has arisen on the basis of a specific nutritional disorder. From what has been said, it is clear that modern organopathology must be understood mainly from the point of view of the local reflection of the action of general pathogenic factors and pathological states of the organism on the structure and function of individual organs.