Motility, Gastroparesis, Non-ulcer Dyspepsia

Question 1

2 processes that need to happen for storage of food in the stomach?

Answer 1

Receptive relaxation: swallowing -> vagus -> pre-emptive relaxation.
Accomodation: Gastric mechanoreceptors -> vasovagal response.

Question 2

What are the “pacemaker” cells of the stomach?

Answer 2

The interstitial cells of Cajal (maybe?)

Question 3

What are gastric slow waves?

Answer 3

Contractions at 3 per minute… which is the maximum rate.

Question 4

What are the 2 physical gastric processes in food processing?

Answer 4

Mixing waves (mixing contractions).
Retropulsion (stuff doesn't get through to duodenum).

Question 5

What’s the process for food emptying called?

Answer 5

Pyloric pump - contractions become strong enough to overcome retropulsion.

Question 6

Different between gastric emptying rates between solids and liquids?

Answer 6

Liquids empty more quickly when there’s more liquid (and thus pressure), thus faster initially.
Food empties faster when it’s been processed to become more liquidy, thus faster later on.

Question 7

How does the duodenum regulate gastric emptying?

Answer 7

Both neuronally and hormonally.

Question 8

What activates the duodenum to slow gastric emptying?

Answer 8

Too much acid
High protein or high fat
Excessive volume
Hypertonic fluids

Question 9

3 enterogastric feedback pathways to slow gastric empyting?

Answer 9

Inhibitory vagal efferent nerve.
Enteric nerves connecting duodenum and stomach (the neuronal part of duodenum regulating gastric emptying).
Sympathetics (inhibitory).

Question 10

4 hormones from the duodenum that slow gastric emptying? Which is most important?

Answer 10

Cholecystikinin (CCK) - most important
Somatostatin
Dopamine
Secretin

Question 11

How does a penny get out of your stomach?

Answer 11

the brief phase strong, lumen-occluding contractions will sweep it out.

Question 12

What is the set of stomach contractions that occur while fasting called?

Answer 12

Migrating motor complex (MMC)

Question 13

3 phases of an MMC?

Answer 13

Long phase I - no contractions
Shorter phase II - few irregular contractions
Brief phase II - intense, lumen-occluding contractions.

Question 14

What molecule promotes brief phase III contractions of MMCs? (What drug agonizes this effect?)

Answer 14

motilin

erythromycin is a motilin agonist

Question 15

What is gastroparesis?

Answer 15

Stuff doesn’t get to the duodenum

Question 16

4 major causes of gastroparesis?

Answer 16

Idiopathic, post-surgical, diabetic, medication-related. (others include… paraneoplastic, rheumatologic, neurologic, myopathic)

Question 17

What might be a cause of some idiopathic gastroparesis?

Answer 17

Post-viral neuropathy..

Question 18

Clinical manifestations of gastroparesis?

Answer 18

Nausea, vomiting, early satiety, postprandial abdominal distension, postprandial abdominal pain.
(makes sense)

Question 19

What’s a bezoar?

Answer 19

A hardened mass of food blocking things up.

Can form in gastroparesis.

Question 20

How is gastroparesis diagnosed? What’s the cutoff for abnormal?

Answer 20

Gastric scintigraphy - eat radioactive egg beaters.

Abnormal: >60% retention at 2 hrs or >10% retention at 4 hrs.

Question 21

What kinds of diets are good recommended for gastroparesis?

Answer 21

Small, frequent, low fat, low-residue (i.e. fiber).

Question 22

2 types of medications for gastroparesis?

Answer 22

Prokinetic agents

Antiemetics

Question 23

Things to be done as last resort for really bad gastroparesis?

Answer 23

Gastric electric stimulation

Surgery

Question 24

What are 3 prokinetic agents used in gastroparesis? What kinds of drugs are they?

Answer 24

Dopamine agonists: metoclopramide, domperidone.

Motilin agonist: erythromycin

Question 25

Indications for enteral nutrition? (4 things)

Answer 25

Severe weight loss, recurrent dehydration, inability to absorb medications, need for gastric decompression.

Question 26

What’s the opposite of gastroparesis? What are its two forms? Common cause?

Answer 26

Dumping syndrome - can be early or late.

Common cause = gastrojejunosostomy (bypass surgery)

Question 27

What is early dumping syndrome? (symptoms etc.)

Answer 27

Nausea, flushing, diarrhea, syncope due to release of vasoactive factors

Question 28

What is late dumping syndrome?

Answer 28

Recall from endo: insulin overreaction -> postprandial hypoglycemia

Question 29

What’s Non-Ulcer Dyspepsia (NUD)?

Answer 29

Can’t find any structural disease… upper GI symptoms

Question 30

2 things that NUD patients may have in common?

Answer 30

Motility probelms
Visceral hypersensitivity (which may be secondary to stress, psych things)

Question 31

Meds for NUD?

Answer 31

Antisecretory (PPIs, H2 antagonists)
Prokinetics
Gastric compliance enhancers…
Visceral perception blockers (eg. TCAs)