Hormones of digestion

Question 1

What are the hormones involved in GI function?

Answer 1

1. Secretin
2. Gastrin
3. Cholecystokinin
4. Incretins
5. Motilin
6. Ghrelin

Question 2

Where is secretin produced and what are its functions?

Answer 2

• Produced: S-cells (duodenum)
• Stimulus: Acid
• Functions:
  1. Promotes pancreatic growth
  2. Stimulates pancreatic secretion
  3. Inhibits gastric acid secretion
  4. Inhibits gastric motility
  5. Stimulates constriction of pyloric sphincter

Question 3

Where is gastrin produced and what are its functions?

Answer 3

• Produced: G-cells (duodenum, gastric antrum)
• Stimulus:
  1. Nervous
  2. Peptides
  3. Amino acids
• Functions:
  1. Stimulates gastric acid secretion
  2. Promotes growth of oxyntic mucosa

Question 4

Where is CCK produced and what are its functions?

Answer 4

• Production: I cells (duodenum/jejunum)
• Stimulus:
  1. Free fatty acids
  2. Monoglycerides
• Functions:
• Stimulates gallbladder contraction
• Stimulates pancreatic secretion
• Promotes pancreatic growth
• Inhibits gastric emptying
• Inhibits appetite

Question 5

What are the incretins?

Answer 5

1. GIP (secreted by upper small intestine after meal)
2. GLP-1 (secreted by Gi tract from jejunum-rectum after meal)

Question 6

What are the functions of incretins?

Answer 6

Controls insulin release from the pancreas

Question 7

Where is motilin produced and what are its functions?

Answer 7

• Production: M cells (upper small intestine)
• Stimulus: Nervous
• Functions:
  1. Initiates MMC
  2. Promotes smooth muscle contraction in GI tract