<P> At the same time, sodium ions are actively reabsorbed . This means that the majority of secreted K and Na ions return to the cytoplasm . In the canaliculus, secreted hydrogen and chloride ions mix and are secreted into the lumen of the oxyntic gland . </P> <P> The highest concentration that gastric acid reaches in the stomach is 160 mM in the canaliculi . This is about 3 million times that of arterial blood, but almost exactly isotonic with other bodily fluids . The lowest pH of the secreted acid is 0.8, but the acid is diluted in the stomach lumen to a pH between 1 and 3 . </P> <P> There is a small continuous basal secretion of gastric acid between meals of usually less than 10 mEq / hour . </P> <P> There are three phases in the secretion of gastric acid which increase the secretion rate in order to digest a meal: </P>

Explain three (3) roles of hydrochloric acid found in the stomach