Which statement about the effect of the distal ileum on gastric emptying is true?

Which statement about the effect of the distal ileum on gastric emptying is true?

• A. It decreases gastric emptying
• B. It increases gastric emptying
• C. It accelerates gastric emptying
• D. It has no effect on gastric emptying

Answer: (A)

The distal ileum engages the ileal brake, a feedback mechanism that slows gastric emptying to give the small intestine more time to digest and absorb nutrients. When nutrients, especially fatty acids, reach the distal ileum, enteroendocrine L-cells release hormones such as peptide YY and GLP-1. These hormones act to reduce antral contractions and increase pyloric resistance, effectively decreasing the rate at which the stomach empties its contents into the small intestine. This is why the statement that the distal ileum decreases gastric emptying is true. The other options—increasing, accelerating, or having no effect—don’t fit because the ileal brake actively slows, not speeds up, gastric emptying, and it does have a regulatory effect.

The distal ileum engages the ileal brake, a feedback mechanism that slows gastric emptying to give the small intestine more time to digest and absorb nutrients. When nutrients, especially fatty acids, reach the distal ileum, enteroendocrine L-cells release hormones such as peptide YY and GLP-1. These hormones act to reduce antral contractions and increase pyloric resistance, effectively decreasing the rate at which the stomach empties its contents into the small intestine. This is why the statement that the distal ileum decreases gastric emptying is true. The other options—increasing, accelerating, or having no effect—don’t fit because the ileal brake actively slows, not speeds up, gastric emptying, and it does have a regulatory effect.