Introduction to GI Physiology

Question 1

Somatostatin

Answer 1

Secreted by D cells.
Stimulated by low luminal pH.
Inhibits gastric H+ secretion.
Inhibits secretion of other GI hormones.
Can be secreted by hypothalamus.

Question 2

Histamine

Answer 2

Stored and secreted by enterochromaffin-like (ECL) cells in gastric glands.
Acts on parietal cells to stimulate acid production.

Question 3

Enteroendocrine cells (EEC)

Answer 3

Contains secretory granules w/ hormones that are released upon stimulation.

Question 4

Gastrin

Answer 4

Increases gastric H+ secretion.

Stimulates growth of gastric mucosa.

Question 5

CCK

Answer 5

Increase pancreatic enzyme secretion.
Increases HCO3- by activating secretin.
Stimulates contraction of Gb.
Inhibits gastric emptying.

Question 6

Secretin

Answer 6

Increase HCO3-
Increase biliary HCO3- secretion
Decreases gastric H+ secretion.
Inhibits trophic effect of gastrin on gastric mucosa.

Question 7

GIP

Answer 7

Increases insulin secretion.

Decreases gastric H+ secretion.