Gastrointestinal Hormones

Question 1

Motillin

Answer 1

Stimulus : alkaline pH in duodenum
Produced by: M-cells
Going to: circulation and pancreas
Function: Motility, peristaltic contractions in SM

Question 2

Gastrin

Answer 2

Stimulus : stomach distention, N. vagus, AA in stomach
Produced by: G-cells
Going to: Parietal cells (pylorus, duodenum, pancr.)
Function: Stimulates secretion of HCl

Question 3

Cholesystokinin

Answer 3

Stimulus : precense of FA or AA in chyme, duodenum
Produced by: I-cells
Going to: liver & pancreas
Function: stimulate digestion of fat and protein

Question 4

Secretin

Answer 4

Stimulus : low duodenal pH (2-4,5)
Produced by: S-cells
Going to: pancreas
Function: neutralize pH in duodenum, allowing digestive enzymes to function properly.

Question 5

Histamine

Answer 5

Stimulus : gastrin
Produced by: ECL (enterochromaffine like cells)
Going to: parietal cells
Function: induce uptake of CO2 and water from blood –> incr prod. of HCl

Question 6

Somatostatin

Answer 6

Stimulus : low pH

Produced by: D-cells, pancreas
Going to: parietal, chief and ECL cells (G-protein coupled receptors)
Function: inhibits activation hormones

Question 7

Leptin

Answer 7

Stimulus : insulin
Produced by: Adipocytes
Going to: Hypothalamus
Function: satiety, antagonist of ghrelin

Question 8

Ghrelin

Answer 8

Stimulus : empty stomach
Produced by: ghrelinergic cells in GIT
Going to: hypothalamus
Function: incr. hunger and gastric acid secretion

Question 9

Substance -P

Answer 9

Stimulates vomiting reflex, released from sensory nerves

Question 10

VIP - vasoactive intestinal peptide

Answer 10

Stimulus : nerve signals
Produced by: nerve cells
Going to: gut, pancreas (G-protein coupled receptors)
Function: relaxes SM in GIT, inhibits gastric acid prod.

Question 11

GIP - gastric inhibiting peptide

Answer 11

Stimulus: high level of glucose in duodenum
Produced by: K- cells
Going to: pancreas (B-cells)
Function: increase insulin production