Pharmaco

Question 1

Increases GI motility

Answer 1

ACh, Substance P, serotonin

Question 2

Decreases GI motility

Answer 2

VIP/NO/ATP, NE/Epi, Opioids (morphine)

Question 3

Increase stomach acid

Answer 3

Gastrin, histamine, ACh, NSAIDs, alcohol

Question 4

Decreases stomach acid

Answer 4

Somatostatin, prostaglandin PGE2

Question 5

What does CCK do? Where is it released?

Answer 5

Increase gallbladder contraction and bile secretion, increase zymogen secretion from pancreas; released in duodenum

Question 6

What do incretins like GIP/GLP do? Where is it released?

Answer 6

Increase insulin release; duodenum

Question 7

Where is secretin released? What does it do?

Answer 7

Duodenum, increases HCO3- release by pancreas

Question 8

What does dopamine do?

Answer 8

D1 receptors - more cAMP, increases gastric motility, causes receptive relaxation, more ACh release
D2 receptors - less cAMP

Question 9

How does stomach respond between meals?

Answer 9

Less acid, more mucus

Question 10

How does stomach respond after meals?

Answer 10

More acid, less mucus - parietal cell cannaliculi emerge, proton pumps are exposed to lumen

Question 11

What produces the acid and mucus?

Answer 11

Acid - parietal cells

Mucus - Mucous cells/Goblet cells

Question 12

What does PGE2 do?

Answer 12

Decreases acid and increases mucus release

Question 13

How can aspirin cause gastric ulcers?

Answer 13

It is a COX inhibitor, which lowers production of PGE2. This means more acid and less mucus are produced. Leads to gastric ulcers.

Question 14

How can you clinically decrease acid secretion (which drugs?)

Answer 14

-prazoles (proton pump inhibitors) - irreversible inhibitor
-tidines (H2/histamine blockers) - reversible inhibitor
Prostaglandins - used with patients who need NSAIDs
Muscarinic blockers (not very good)

Question 15

What are antacids? What are the two types?

Answer 15

Bases that neutralize gastric acid, can be bicarbonate or hydroxide salts

Systemic antacids - cause systemic alkalosis
Nonsystemic antacids - stay in GI tract

Question 16

What do they typically use for an antacid?

Answer 16

MgOH2 and AlOH3 which cause diarrhea and constipation respectively, thus off-setting each other and neutralizing gastric acid

Question 17

What are mucosal protective agents?

Answer 17

Cover gastric surface with artificial mucus or stimulate mucus secretion
Ex: Pepto-Bismol, Sucralfate

Question 18

What are prokinetic drugs?

Answer 18

Promote motility to improve gastric emptying; relax pyloric sphincter and tighten lower esophageal sphincter
Ex: Metoclopramide - dopamine blocker that affects D1 and D2
D2 blocking –> more ACh release, increases GI motility overall
D1 blocking –> inhibition of receptive relaxation

Question 19

What is an opioid derivative that slows GI motility and stays in GI tract with few side effects?

Answer 19

Imodium/loperamide

Question 20

How do anti-emetics work?

Answer 20

Vomiting is promoted by ACh, prevented by ACh antagonists, so muscarinic antagonists like Scopolamine patches prevent motion sickness