Digestive physiology: Which of the following is an example of a digestive hormone (not an enzyme) that regulates gastric function?

Introduction / Context:
Digestion involves both enzymes that catalyze hydrolysis of food and hormones that regulate secretion and motility. Recognizing the difference is fundamental in physiology.

Given Data / Assumptions:

• Lipase, pepsin, and amylase are hydrolytic enzymes.
• Gastrin is a peptide hormone released from G cells of the stomach.
• We are asked to pick the hormone among enzymes.

Concept / Approach:
Gastrin stimulates gastric acid secretion by parietal cells and promotes gastric mucosal growth and motility. Enzymes like pepsin (protease), lipase (fat hydrolysis), and amylase (starch digestion) are produced in zymogen or active forms and act directly on substrates.

Step-by-Step Solution:
Classify each option: enzymes vs hormone.Identify gastrin as the hormone controlling gastric physiology.Conclude gastrin is the correct choice.

Verification / Alternative check:
Clinical tests measuring serum gastrin (e.g., in Zollinger–Ellison syndrome) confirm its endocrine role distinct from digestive enzymes.

Why Other Options Are Wrong:

• Lipase, pepsin, amylase: all are enzymes, not hormones.

Common Pitfalls:
Confusing naming conventions; many digestive factors are peptides, but only some are secreted as hormones that act on receptors to regulate function.

Final Answer:
gastrin