Gastrointestinal Hormones and Regulation

Question 1

Action and secretion site of Gastrin

Answer 1

Increase Gastric acid secretion from Parietal cells; G cells of gastric antrum and duodenum

Question 2

Action and secretion site of Somatostatin

Answer 2

Decrease secretion of most GI hormones: gastric acid and pepsinogen, pancreatic juices, gallbladder, insulin and glucagon; D cells of pancreatic islets and gut mucosa

Question 3

Action and secretion site of Cholecystokinin

Answer 3

Increase pancreatic enzyme and Bicarb secretion; I cells of small intestine

Question 4

Action and secretion site of Secretin

Answer 4

Increase pancreatic bicarb secretion and decrease gastric HCl secretion; S cells of the small intestine

Question 5

Action and secretion site of GIP

Answer 5

Increase insulin release and decrease gastric HCl secretion; K cells of small intestine

Question 6

Action and secretion site of Motilin

Answer 6

Increase GI motility; M cells of small intestine

Question 7

Action and secretion site of Vasoactive intestinal peptide

Answer 7

Increase intestinal water and electrolyte secretion and relaxation of intestinal smooth muscle and sphincters; Parasympathetic ganglia

Question 8

Action and secretion site of Intrinsic factor

Answer 8

Vit B12 binding protein–required for B12 absorption in the ileum; Parietal cells of the stomach

Question 9

Action and secretion site of Pepsinogen

Answer 9

Protein digestion in stomach, Pepsinogen activated to Pepsin by HCl; Chief cells of the stomach

Question 10

Action and secretion site of Trypsinogen

Answer 10

Activation of other proenzymes and itself once activated to Trypsin by enterokinase/enteropeptidase (brush-border enzymes); Pancreas