GI tract Secretion

Question 1

Primary regulatory events in the intestinal phase - if pH > 3

Answer 1

duodenal peptides / amino acids cause release of gastrin

Question 2

Primary regulatory events in the intestinal phase - if pH < 2

Answer 2

gastric inhibition and intestinal stimulation

Question 3

Duodenal fats and breakdown products cause

Answer 3

release of GIP and CCK

Question 4

Acid entering intestine causes

Answer 4

secretin release

Question 5

salivary secretion functions

Answer 5

• Initial digestion of starches and lipids (very little)
• Dilution and buffering of ingested foods
• Protection of teeth and gums
• Lubrication of ingested foods with mucous (mucin)

Question 6

direct pathway somatostatin:

Answer 6

–binds to receptors on parietal cells (and inhibits adenylate cyclase via Gi protein so inhibits HCl release)

Question 7

indirect pathway somatostatin:

Answer 7

inhibits histamine release from stomach and gastrin release from G cells so HCl inhibited

Question 8

Innervation of pancreas

Answer 8

• Parasympathetic innervation from the vagus stimulates secretion
• Sympathetic innervation inhibits secretion

Question 9

pancreatic enzymes stored and condensed in

Answer 9

Stored in condensed zymogen granules until release

Question 10

3 types of enzymes:

Answer 10

• Pancreatic amylase
• Pancreatic lipase
• Proteolytic

Question 11

3 major proteolytic enzymes:

Answer 11

 Trypsinogen
 Chymotrypsinogen
 Procarboxypeptidase