Final answer:
The statement is false; secretin does not reduce blood pH but instead prompts the pancreas to secrete bicarbonate, which neutralizes the acidity of chyme in the intestine.
Step-by-step explanation:
The statement secretin of gastric juice will reduce the pH of the blood is false. Secretin is a hormone, but it is not a component of gastric juice; instead, it is released by the duodenum (part of the small intestine) when acidic chyme enters from the stomach. Secretin's primary function is to prompt the pancreas to release bicarbonate into the small intestine, which neutralizes the acidic chyme from the stomach, thereby increasing the pH of the contents in the intestine, not reducing the blood pH.
Consider, also, that if the pH in the duodenum is too low (which means more acidic), secretin will be released, leading to the production of bicarbonate by the pancreas, which neutralizes the acidity. This ensures that the acidic stomach contents do not damage the intestine and provides an optimal pH for the action of digestive enzymes. Therefore, secretin actually helps to maintain balance in the digestive system, ensuring that extremes in acidity do not occur. The interplay between gastric juices and secretin is a fine example of the body's regulatory mechanisms to maintain homeostasis, particularly pH balance in the digestive tract.