GI

Question 1

cholecystokinin (CCK)

Answer 1

• I cells (duodenum, jejunum)
• increases pancreatic secretion, gallbladder contraction, sphincter of Oddi relaxation
• decrease gastric emptying
• regulation: increased by FA and AA

Question 2

gastrin

Answer 2

• G cells (antrum of stomach)
• increases gastric H+ secretion, growth of gastric mucosa, gastric motility
• regulation: increased by stomach distention/alkalinization, AA, peptides, vagal stimulation; decreased by stomach pH

Question 3

glucose-dependent insulinotropic peptide (GIP)

Answer 3

• K cells (duodenum, jejunum)
• exocrine: decreases H+ secretion
• endocrine: increases insulin release
• regulation: increased by fatty acids, aa, oral glucose

Question 4

motilin

Answer 4

• small intestine
• produces migrating motor complexes
• regulation: increases in fasting state

Question 5

secretin

Answer 5

• S cells (duodenum)
• increases pancreatic HCO3- secretion, bile secretion
• decreases gastric acid secretion
• regulation: increased by acid, FA in lumen of duodenum

Question 6

somatostatin

Answer 6

• D cells (pancreatic islets, GI mucosa)
• decreases gastric acid and pepsinogen secretion, pancreatic and small intestine fluid secretion, gallbladder contraction, insulin and glucagon release
• regulation: increased by acid, decreased by vagal stimulation

Question 7

nitric oxide

Answer 7

-increases smooth muscle relaxation including lower esophageal sphincter

Question 8

vasoactive intestinal polypeptide (VIP)

Answer 8

• parasympathetic ganglia in sphincters of gallbladder, small intestine
• increases intestinal water and electrolyte secretion, relaxation of intestinal smooth muscle and sphincters
• regulation: increased by distention and vagal stimulation; decreased by adrenergic input

Question 9

intrinsic factor

Answer 9

• parietal cells (stomach)

- vitamin B12 binding protein (uptake in ileum)

Question 10

gastric acid

Answer 10

• parietal cells (stomach)
• decrease stomach pH
• regulation: increased by histamine, ACh, gastrin; decreased by somatostatin, GIP, prostaglandin, secretin

Question 11

pepsin

Answer 11

• chief cells (stomach)
• protein digestion
• regulation: increased by vagal stimulation, local acid

Question 12

HCO3-

Answer 12

• mucosal cells (stomach, duodenum, salivary, pancreas)
• Brunner glands (duodenum)
• neutralize acids
• regulation: increased by biliary secretion w/ secretin