Which substance neutralizes chyme in the small intestine and is released by the pancreas in response to secretin?

Which substance neutralizes chyme in the small intestine and is released by the pancreas in response to secretin?

• A. Sodium Bicarbonate
• B. Hydrochloric Acid
• C. Mucus
• D. Bile

Answer: (A)

When acidic chyme from the stomach enters the small intestine, the duodenal lining releases secretin. This hormone signals the pancreas to deliver a bicarbonate-rich fluid into the duodenum. The sodium bicarbonate neutralizes the acidic chyme, raising the pH to around neutral. This neutral environment is essential because pancreatic enzymes (like amylase, lipase, and proteases) and other intestinal enzymes work best at higher pH levels and would be inhibited by strong acidity. Mucus protects the lining, and bile helps digest fats, but neither is the neutralizing agent released by the pancreas in response to secretin.

When acidic chyme from the stomach enters the small intestine, the duodenal lining releases secretin. This hormone signals the pancreas to deliver a bicarbonate-rich fluid into the duodenum. The sodium bicarbonate neutralizes the acidic chyme, raising the pH to around neutral. This neutral environment is essential because pancreatic enzymes (like amylase, lipase, and proteases) and other intestinal enzymes work best at higher pH levels and would be inhibited by strong acidity. Mucus protects the lining, and bile helps digest fats, but neither is the neutralizing agent released by the pancreas in response to secretin.