The Major Stimulus for Secretin Secretion Is

Question

The major stimulus for secretin secretion is A) Mechanical irritation of the duodenum B) H⁺ in the duodenal lumen C) Distension of the duodenum D) Amino acids in the duodenum E) Fat digestion products in the duodenum

Accepted Answer

The major stimulus for secretin secretion is the presence of acidic contents (low pH) in the duodenum. This is represented by "H⁺" in the choices, which seems to be a typographical error but implies the presence of acid (H+ ions) in the duodenal lumen.