345 - Physiology

Question 1

What is the source of cholecystokinin?

Answer 1

I cells (duodenum, jejunum)

Question 2

What are the actions of cholecystokinin?

Answer 2

↑ pancreatic secretion
↑ gallbladder contraction
↓ gastric emptying
↑ sphincter of Oddi relaxation

Question 3

How is cholecystokinin regulated?

Answer 3

↑ by fatty acids and amino acids

Question 4

Through which pathway does CCK cause pancreatic secretion?

Answer 4

muscarinic pathways

Question 5

What is the source of gastrin?

Answer 5

G cells (antrum of stomach)

Question 6

What are the actions of gastrin?

Answer 6

↑ gastric H+ secretion
↑ growth of gastric mucosa
↑ gastric motility

Question 7

how is gastrin regulated?

Answer 7

↑ by stomach distention/alkalinization, amino acids, peptides, vagal stimulation
↓ by stomach pH < 1.5

Question 8

In what syndrome is gastrin classically elevated?

Answer 8

Zollinger-Ellison syndrome

Question 9

What is the effect of chronic PPI use on gastrin?

Answer 9

↑

Question 10

What is the effect of phenylalanine and tryptophan on gastrin?

Answer 10

potent stimulation

Question 11

What is the source of glucose-dependent insulinotropic peptide?

Answer 11

K cells (duodenum, jejunum)

Question 12

What are the actions of glucose-dependent insulinotropic peptide?

Answer 12

Exocrine: ↓ gastric H+ secretion
Endocrine: ↑ insulin release

Question 13

How is glucose-dependent insulinotropic peptide regulated?

Answer 13

↑ by fatty acids, amino acids, oral glucose

Question 14

What is another name for glucose-dependent insulinotropic peptide?

Answer 14

gastric inhibitory peptide (GIP)

Question 15

Secretion of what hormone accounts for the more rapid utilization of glucose upon eating vs. IV delivery?

Answer 15

GIP

Question 16

What is the source of motilin?

Answer 16

small intestine

Question 17

What is the action of motilin?

Answer 17

produces migrating motor complexes (MMCs)

Question 18

How is motilin regulated?

Answer 18

↑ in fasting state

Question 19

What kind of drugs are used to stimulate intestinal peristalsis?

Answer 19

motilin receptor agonists such as erythromycin

Question 20

What is the source of secretin?

Answer 20

S cells (duodenum)

Question 21

What are the actions of secretin?

Answer 21

↑ pancreatic HCO3- secretion
↓ gastric acid secretion
↑ bile secretion

Question 22

What regulates secretin?

Answer 22

↑ by acid, FAs in lumen of duodenum

Question 23

What is the relationship between HCO3- and pancreatic enzymes?

Answer 23

↑ HCO3- neutralizes gastric acid in duodenum, allowing pancreatic enzymes to function

Question 24

What is the source of somatostatin?

Answer 24

D cells (pancreatic islets, GI mucosa)

Question 25

What are the actions of somatostatin?

Answer 25

↓ gastric acid and pepsinogen secretion ↓ pancreatic and small intestine fluid secretion ↓ gallbladder contraction ↓ insulin and glucagon release

Question 26

How is somatostatin regulated?

Answer 26

↑ by acid | ↓ by vagal stimulation

Question 27

What is the overall effect of somatostatin?

Answer 27

It's an inhibitory hormone with antigrowth hormone effects (inhibits digestion and absorption of substances needed for growth)

Question 28

What are the actions of nitric oxide?

Answer 28

↑ smooth muscle relaxation, including lower esophageal sphincter

Question 29

What substance imbalance is implicated in the ↑ LES tone of achalasia?

Answer 29

Loss of NO secretion

Question 30

What is the source of VIP?

Answer 30

Parasympathetic ganglia in sphincters, gallbladder, small intestines

Question 31

What are the actions of VIP?

Answer 31

↑ intestinal water and electrolyte secretion | ↑ relaxation of intestinal smooth muscle and sphincters

Question 32

How is VIP regulated?

Answer 32

↑ by distention and vagal stimulation | ↓ by adrenergic input

Question 33

What is a common tumor that secretes VIP?

Answer 33

VIPoma: a non-α, non-β islet cell pancreatic tumor

Question 34

What are the symptoms of VIPoma?

Answer 34

Watery Diarrhea (copious) Hypokalemia Achlorhydria (aka WDHA syndrome)