Lecture 10: Gastric Motility, Gastroparesis and Non-Ulcer Dyspepsia

Question 1

Function of the stomach:

Answer 1

Fundus and proximal body = storage
-rugae in the fundus
Distal body and antrum = processing/emptying

Question 2

What are the neuronal components of storage?

Answer 2

1. Receptive relaxation
   
   • induced by act of swallowing
   • induces vagal nerve
2. Accomodation
   
   • gastric mechanoreceptors
   • vagovagal response

Question 3

What causes gastric motility?

Answer 3

1. Gastric pacemaker
   -interstitial cell of cajal
   -located at proximal body along greater curvature
2. Gastric SLOW WAVES
   -internal rhythm = 3/minute
   -contraction threshold needed to be reached
   -maximum contraction frequency is 3/minute
   Stomach is like heart because they have a pacemaker cells

Question 4

What is the post-prandial phase of gastric motility?

Answer 4

1. food processing
   
   • mixing wave (mixing contractions)
   • retropulsion
2. food emptying

Question 5

What is Trituration?

Answer 5

Name of several different methods of processing materials

Mixing food

Question 6

What do food solids get released as to duodenum? Liquid?

Answer 6

Gets released as CHYME

Liquid goes through pylorus through an antroduodenal pressure gradient

Question 7

What are the general rules of gastric emptying rate?

Answer 7

Larger volume empties faster than smaller volume
Liquids empty faster than solids
Starch > protein > fat

Question 8

When does duodenum inhibit pyloric pump?

Answer 8

1. too much gastric acid
2. high protein or high fat
3. excessive volume of chyme
4. hypertonic fluid

Question 9

What are the three feedback loops?

Answer 9

1. inhibitory vagal efferent nerve
2. Enteric nerves connecting duodenum and stomach
3. Inhibitory sympathetic nerve fibers

Question 10

What are the hormones negatively inhibit the pyloric pump?

Answer 10

1. Cholecystikinin (CCK)
2. Somatostatin
3. Dopamine
4. Secretin

Question 11

What is the sensation of fullness?

Answer 11

Stretching of mechanoreceptors in the stomach

So compromise of accommodation ability of patient

Question 12

What is the characteristic of the FASTING PHASE of gastric motility?

Answer 12

Characterized by migrating motor complex (120 minutes)

i. long phase I = no contractions
ii. shorter phase II = irregular contractions
iii. brief phase III = INTENSE contractions
	- house-keeping function
	- motilin (erythromycin)
	- sweeps shit like pennies down to anus lol

Question 13

What is motilin?

Answer 13

A hormone that induces phase III (intense contractions) of gastric motility in fasting state

Question 14

What is gastroparesis?

Answer 14

Literally mean stomach paralysis
Impaired transit of food from stomach to the duodenum
Mechanical obstruction is excluded!

Question 15

What are the causes of gastroparesis?

Answer 15

1. idiopathic
2. post-surgical
3. DIABETES
4. neurologic, myopathic, rheumatologic

Question 16

How does diabetes lead to gastroparesis?

Answer 16

Autonomic neuropathy due to high blood sugar levels

Question 17

Why do liquids empty faster with gastroparesis in diabetes?

Answer 17

Because proximal stomach cant relax, therefore the pressure in stomach is higher and liquid goes to duodenum faster

Question 18

What are the clinical manifestations of gastroparesis?

Answer 18

1. nausea
2. vomiting
3. early satiety
4. postprandial abdominal distention
5. postprandial abdominal pain

Question 19

What is a bezoar?

Answer 19

Food and debris in the stomach that is NOT cleared by the migrating motor complex (MMC) as part of fasting

Question 20

How do you manage gastroparesis?

Answer 20

1. small and frequent meals
   Low fat and low residue diet
   Glucose control in diabetic
   Antiemetics and prokinetic agents

Question 21

What are types of prokinetics for gastroparesis?

Answer 21

1. Dopamine antagonists
   
   • metoclopramide
   • Domperidone
2. Motilin agonist
   
   • erythromycin

Question 22

What is Metoclopramide?

Answer 22

1. dopamine antagonist
   Prokinetic that is used for gastroparesis
   Side effects = Arrhythmia, tardrive dyskinesia, excess prolactin

Question 23

What is Domperidone?

Answer 23

Dopamine antagonist
Prokinetic used for gastroparesis
Arrhythmia, tardrive dyskinesia

Question 24

What is erythromycin?

Answer 24

Antibiotic thati s also a MOTILIN agonist
Used for gastroparesis
Side effects = abdominal carmping, nausea, vomiting, interacts with CYP-3A

Question 25

What is dumping syndrome?

Answer 25

1. rapid gastric emptying of hypertonic liquids
2. seen in gastrojejunostomy
3. symptoms include nausea, diarrhea, flushing, relapse of vasoactive factors
4. late dumping symptosm = hypoglycemia

Question 26

What is the definition of non-ulcer dyspepsia or functional dyspepsia?

Answer 26

Post-prandial distress syndrome
Epigastric pain syndrome
Need to have this for 3 months
This is a diagnosis by exclusion
Delayed gastric compliance
Poor gastric compliance
Gastric dysrhythmias
Ineffective antropyloroduodenal contraction

Question 27

What is dyspepsia?

Answer 27

Impaired digestion

Question 28

What is the association between psychiatric disorders and nonulcer dyspepsia?

Answer 28

Stress and psychiatric disorders heighten VISCERAL SENSITIVITY which leads to dyspepsia

Treatment includes PPI, prokinetics and psychiatric therapuy