<prompt> Positive feedback is seen in all exceptLH surgeEntry of calcium into sarcoplasmic reticulumGastric secretionThrombus formation  <response>: Ans. c Gastric secretionRef: Guyton, 13th edp.7Gastric secretion is an example for a negative feedbackIncrease in levels of gastric acid inhibits its own productionPositive feedback - once started, it enhances or amplifies the effect on its own. That is why positive feedback is also called VICIOUS CYCLEExamples of positive feedback are, CLASPClottingLH surgeAction potentialShockParturition 