Mechanisms of cholera

Content

  • Atrium
  • Action Vibrio cholerae in the intestine
  • Mechanisms of involvement of other systems oraganizma



  • Atrium

    Atrium through whichpathogen enters the body, is the digestive tract. However, Vibrio cholerae is often perish in the stomach due to the presence there of hydrochloric (hydrochloric) acid, which actually has a detrimental effect. The disease develops only when the protective mechanism fails, and Vibrio cholerae overcomes gastric barrier. Reaching the small intestine, cholera begins to rapidly proliferate and secrete exotoxin to the external environment. Many of the manifestations of the disease occur under the influence of it exotoxin. In experiments with human volunteers found that a huge dose of Vibrio cholerae cause the disease in individual persons, but after a preliminary neutralization of the hydrochloric acid of the stomach could cause disease after administration of 106 vibrio (t. E. 100 000 times lower dose).



    Action Vibrio cholerae in the intestine

    Occurrence cholera syndrome associated with the presence of the two substances vibrio:

    • protein toxin - the toxin (exotoxin)
    • neuraminidase

    Mechanisms of choleraCholeragen binds to a specific receptorenterocytes - intestinal cells - ganglioside. Neuraminidase, splitting acid residues forms of ganglioside specific receptor, thereby enhancing the effect of the toxin.

    The complex-specific receptor choleragenactivates prostaglandin formation process. These substances and the ion pump is controlled by the secretion of water and electrolytes from the cells in the intestinal lumen. As a result of the activation of the mechanism of the mucous membrane of the small intestine begins to secrete huge amount of fluid into the intestinal lumen, which is not physically have time to absorb the large intestine. Starting profuse liquid diarrhea.

    Rough morphological changes of diseased cellsCholera is not possible to identify. It failed to detect either cholera toxin in the lymph or blood vessels in extending from the small intestine. In this regard, there is no evidence that human toxin affects any other organs except the small intestine.

    Secreted by the small intestine fluid has a low protein content, contains the following electrolytes:

    • sodium
    • potassium
    • bicarbonate
    • chlorides



    Mechanisms of involvement of other systems oraganizma

    Fluid loss reaches 1 liter per hour. As a result, a decrease in plasma volume begins with a reduction in the number of circulating blood and blood thickening. There is a movement of fluid from the intercellular space in the intravascular space, which can not compensate for the continuing loss of the liquid portion of the blood. Therefore rapidly advancing hemodynamic disorders, disturbances of the microcirculation, which lead to dehydration shock (shock from dehydration) and acute renal failure.

    Evolving in shock acidosis (ph offset environmentthe acid side) is enhanced deficit alkalis. Bicarbonate concentration in faeces twice its plasma contents. There is progressive loss of potassium concentration in feces is 3-5 times higher than that of blood plasma.

    If you enter enough fluidsIV, all violations are rapidly disappearing. Incorrect treatment or lack of it leads to the development of acute renal failure and hypokalemia (potassium concentrations decrease in the blood). The latter, in turn, can cause intestinal atony, hypotension, arrhythmias, changes in the myocardium. Termination of renal excretory function leads to azotemia - accumulation in the blood of nitrogenous substances. Circulatory disturbance in brain vessels, acidosis and uremia (urine in the blood) cause disorder of the central nervous system and the patient's consciousness (drowsiness, stupor, coma).

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