Circulus Vitiosus

CIRCULUS VITIOSUS (Latin), literally a vicious circle. Under C. v. in medicine and pathology are mainly understood such phenomena when pathological consequences arising from one or another cause themselves become the cause of new complications or worsen the course of the initial process. Thus, during starvation, with a number of avitaminoses, for example with pellagra, easily arising disorders of the gastrointestinal tract lead to the fact that the absorption of nutrients, in particular the anti-pellagric vitamin, is further impaired, and the resulting disorders themselves become a new, endogenous factor in the development of exhaustion or the same pellagra. Congestive phenomena that arise in the small and large circles of circulation with heart defects lead to brown induration of the lungs, edema, metabolic disorders, etc., but then these changes themselves become the cause of respiratory and circulatory disorders, making the course of the main disease more severe. General disorders of calcium metabolism (with rickets, osteomalacia, with fibrous osteitis, etc.) often lead to a hyperplastic state of the parathyroid glands. But in turn this hyperplasia itself becomes a powerful factor in the development or fixation of the disturbed metabolism. Since we do not study pathological phenomena in isolation from physiological phenomena, the concept of a 'circle' of phenomena can be transferred to the field of physiology (circulus physiologicus). Thus, the gastric mucosa during the height of the digestive process secretes secretions not only into the cavity of the stomach but also into the blood and lymph, and these substances, circulating in the blood, further promote secretion and digestion itself. Similar phenomena are encountered in the secretion of milk, bile, etc. In the simplest cases, under C. v. are understood purely mechanical disorders, for example those that sometimes arise after gastroenterostomy operations, when food from the stomach is expelled through the duodenum only to again enter the stomach through the artificial opening, etc.