Gastric Motility & Dyspepsia

Question 0

What is responsible for the accommodation of the proximal stomach?

Answer 0

Gastric mechanoreceptors and a vagovagal response.

Question 1

What is responsible for the receptive relaxation of the proximal stomach?

Answer 1

A swallowing-induced vagal response.

Question 2

What serves as the gastric pacemaker?

Answer 2

The interstitial cells of Cajal along the greater curvature of the proximal stomach.

Question 3

What is the frequency for gastric slow waves?

Answer 3

3 per minute.

Question 4

What 3 factors determine the gastric emptying rate?

Answer 4

(1) food volume
(2) food consistency
(3) food content

Question 5

What food profile would result in the fastest emptying rate? Slowest?

Answer 5

Fastest: a large volume of liquid
Slowest: a small volume of solid

carbohydrates > protein > fat

Question 6

What can trigger inhibition of the pyloric pump (either neuronal or hormonal) by the duodenum?

Answer 6

(1) too much gastric acid
(2) high protein or high fat
(3) excessive volume of chyme
(4) hypertonic fluids

Question 7

What are the 3 sources of neuronal feedback on the pyloric pump?

Answer 7

(1) inhibitory vagal efferent nerve
(2) enteric nerves connecting the duodenum to the stomach
(3) inhibitory sympathetic nerves

Question 8

What hormones inhibit gastric emptying?

Answer 8

(1) cholecystokinin
(2) somatostatin
(3) dopamine
(4) secretin

Question 9

J: This refers to an impaired transit of food from the stomach to the duodenum, not caused by a mechanical obstruction.

Answer 9

What is gastroparesis?

Question 10

What are causes of gastroparesis?

Answer 10

(1) diabetes mellitus
(2) surgery (gastric, esophageal, thoracic)
(3) idiopathic (viral?)
(4) medication

Question 11

What is the clinical presentation of gastroparesis?

Answer 11

(1) nausea and vomiting
(2) early satiety
(3) post-prandial distention and pain

Question 12

How is gastroparesis diagnosed?

Answer 12

Through a gastric-emptying test using radiolabelled egg substitute.

Question 13

How is gastroparesis treated?

Answer 13

(1) small and frequent meals
(2) low-fat and low-residue diet
(3) pro-kinetic agents
(4) antiemetics
(5) gastric electric stimulation
(6) surgery

Question 14

What is the role of brief phase III during fasting?

Answer 14

To perform gastric house-keeping. It consists of 5-10 minutes of intense contractions (every ~1.5 hours), stimulated by motilin.

Question 15

What are the 7 classes of pro-kinetic agents?

Answer 15

(1) dopamine antagonists
(2) motilin agonists
(3) muscarinic agonists
(4) acetylchlinesterase inhibitors
(5) opioid receptor antagonists
(6) CCK receptor antagonists
(7) 5-HT4 agonists

Question 16

What are the notable dopamine antagonists used for gastroparesis?

Answer 16

(1) metoclopramide

(2) domperidone

Question 17

What are adverse effects of dopamine antagonists?

Answer 17

(1) increased prolactin

(2) arrhythmias?

Question 18

How does erythromycin work as a pro-kinetic agent?

Answer 18

It is a motilin agonist.

Question 19

What are adverse effects of erythromycin?

Answer 19

(1) abdominal cramping
(2) nausea
(3) vomiting

Question 20

What are the 8 classes of antiemetic agents?

Answer 20

(1) dopamine antagonists
(2) 5-HT3 antagonists
(3) tricyclic antidepressants
(4) M1 antagonists
(5) H1 antagonists
(6) cannabinoids
(7) neurokinin antagonists
(8) benzodiazepines

Question 21

When is gastric electric stimulation an indicated treatment?

Answer 21

Chronic, intractable nausea and vomiting due to diabetic or idiopathic gastroparesis.

Question 22

What is the MoA of gastric electric stimulation?

Answer 22

Unknown.

Question 23

What surgery is performed for the purpose of initiating enteral nutrition?

Answer 23

Jejunostomy.

Question 24

What is the clinical presentation of early dumping syndrome?

Answer 24

(1) nausea
(2) flushing
(3) diarrhea
(4) syncope

Question 25

What is the clinical presentation of late dumping syndrome?

Answer 25

Hypoglycemia.

Question 26

How is non-ulcer dyspepsia defined?

Answer 26

(1) post-prandial distress syndrome
(2) epigastric pain
(3) no structural disease
(4) symptoms for > 3 months

Question 27

J: This refers to a psychological etiology for non-ulcer dyspepsia.

Answer 27

What is visceral hypersensitivity?