Question

how is the required pH maintained in the stomach and intestine?

Answer 1

Gastric acid or the digestive juice, formed in the stomach is composed of hydrochloric acid (HCl)  and large quantities of potassium chloride (KCl) and sodium chloride (NaCl).  The stomach contains parietal (oxyntic) cells that secrete HCL. The HCL creates acidic pH in the stomach necessary for the action of enzyme pepsin. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring that it does not become too acidic. The pH of gastric acid is 1.35 to 3.5 in the human stomach, the acidity being maintained by the proton pump H+/K+ ATPase. The small intestines has a pH of around 7 to 8, that is, it is either neutral or slightly alkaline in nature. The  pancreas secretes the bicarbonate ions through bile juice in the small intestines. These bicarbonates neutralize the acidic pH of the food from stomach and create an alkaline pH,  thus maintain the required pH in small intestines........................

Answer 2

Explanation:

pH of Stomach is 1.2 to 3.4 , which is acidic .