Question

Is the pH of the small intestine lower or higher than that of the stomach? Why is the pH of the small intestine not the same as that of the stomach?

Answer 1

After swallowing, the meal reaches the stomach, where the pH levels in the upper and lower sections of the stomach differ. The upper half has a pH of 46.5, while the lower part has a pH of 1.54-0, making it severely acidic. It subsequently reaches the gut, which has a pH of 78.5 and is slightly alkaline.

Complete answer:
Because gastric lipase and HCl are necessary to chemically digest most foods, the stomach is extremely acidic.
Because other digestive enzymes for chemical digestion, such as pancreatic lipase, gall, trypsin, and pepsin, are not as acidic as the chemicals in the stomach, the acids in the intestines are weaker and more diluted.

In the stomach, the pH rarely, if ever, falls below 3.0. When stomach acid first reaches the stomach, it has a pH of 1.8, but this is immediately diluted when food is present. Plant enzymes, on the other hand, are not damaged by the stomach's highly acidic environment. They merely go dormant until they reach higher pH levels in the small intestine, at which point they reawaken and resume the digestion process. A considerable number of enzymes are absorbed into the bloodstream once their digesting role in the gastrointestinal system is accomplished.

The pH of the small intestine gradually rises. The duodenum has a pH of 6, while the Jejunum has a pH of 7 to 9, and the Ileum has a pH of 7.4. The pancreas releases sodium bicarbonate to keep pH levels stable.

Note:
Between the stomach and the rest of the small intestine is the duodenum, a brief segment of the small intestine. The hormone secretin is produced in the duodenum to induce the pancreatic secretion of significant amounts of sodium bicarbonate, which increases the chyme's pH to 7.