Vicious circle

Vicious circle (circulus vitiosus) is a chain of pathological changes related cause-effect relationships so that one consequence of the pathological process causes the further development of this process. So, heart failure at his vices leads to decreased cardiac output, increase of venous pressure, and other hemodynamic shifts; this includes neuroendocrine mechanisms, causing hypersecretion of aldosterone, which causes a delay of Sodium and water in the body. The result is a swelling in the tissues, including in the myocardium, and gipervolemia, which creates additional load on the heart, increasing his overall failure (see heart Defects).
When interacting with the environment, the body both in normal conditions and in pathology reacts as a single integrated system. Therefore, the impact of any factor that causes changes in a number of organs and systems. With the development of the pathological process are included protective-adaptive mechanisms aimed for his liquidation and compensation of impaired functions. Therefore, at a certain stage of development of pathological reactions are destroyed or weakened compensatory devices (see) and can be hidden. When sufficient compensatory reactions painful process may stop at this stage of development. If the power of immune response is insufficient, you may encounter a vicious circle: the consequence of the primary causes of the disease in certain conditions can lead to the same changes in the systems of organs, which calls itself a cause.
The vicious circle can occur with equal diseases, and its mechanism may be different. According to M. I. astvatsaturova, there are several kinds of vicious circle. The simplest example it is often a vicious circle caused by mechanical conditions. So, for example, increased intracranial pressure (reason) leads to the compression of v. magna Galeni, causing stagnation in the vascular plexus of the ventricles of the brain; resulting in the increase in the allocation of cerebrospinal fluid, and consequently further increase in intracranial pressure. The limited mobility of joints in the contracture is accompanied by changes ligaments that in turn causes even more significant restriction of joint movement.
Of particular interest are the form of a vicious circle, which are based on the brake and stimulating the interaction of various functional mechanisms. In these cases, the consequence of the pathological process are dynamic changes due to the primary process. For example, each epileptic seizure is the result of previous and cause subsequent seizure. The great value has a vicious circle, due to the interaction of mental and somatic processes. For example, in diffuse toxic goiter gipertireoidizmom and the associated increase the tone of the sympathetic nervous system has the consequence of strengthening emotive activities. The latter is the reason for the tone of the sympathetic nervous system and in turn causes increased secretion of the thyroid gland (see diffuse toxic Goiter).
The mechanism of the vicious circle leads to certain conditions, to what is known symptom at various stages of the pathological process may be due to various reasons. In the mechanism of development of a vicious circle, not all stages of this process can be classified as pathological, part of them provides compensatory-adaptive reactions of the organism. In turn and compensatory reaction at different stages of the disease may reach this intensity, which brings no benefit and harm, increasing manifestations of a vicious circle. So, vomiting, being protective and adaptive reactions of the body, are aimed at removing harmful acting agent and restoration of impaired functions. At the same time, repeated vomiting (for example, uncontrollable vomiting pregnant) can lead to a sharp deterioration of the body due to loss of fluids and electrolytes fabrics, pH of blood, etc.
For successful pathogenetic therapy of the disease is necessary at each stage of the disease to identify, decrypt causal link between taking place in the organism processes.
Thus, important in the prevention of a vicious circle and combat it gets a proper assessment of what is happening in the body of the phenomena with the aim of eliminating the causes of functional and structural components of the pathological process and strengthening of protective-adaptive and reparative reactions that provides optimal conditions for compensation of impaired functions.