Zaczek RS 1- GI Motility

Question 1

What are the differences between a primary and secondary peristalsis?

Answer 1

A primary peristalsis is initiated by swallowing and abolished by a vagotomy

A secondary peristalsis is not initiated by a swallow, but rather by distention in the esophagus

It is ENS-mediated and not abolished by a vagotomy

Question 2

What occurs in the orad stomach during the fasted state? Fed state?

Answer 2

In the fasted state, tonic, low amplitude contractions are occurring to promote an intragastric concentration gradient that favors gastric emptying

In the fed state, the swallowing center drives receptive relaxation.

Distention drive accommodation via long-loop vagovagal reflexes

Question 3

What chemicals are released to maintain gastric accomodation?

Answer 3

VIP and NO

Question 4

What is occurring in the caudad stomach during the fasted state? During the fed state?

Answer 4

In the fasted state, migrating motor complexes (MMC’s) occur every 90-120 minutes as a form of housekeeping contractions

In the fed state, there is continuous peristalsis and a heightened tone of the pyloric sphincter

Question 5

What is achalasia?

Answer 5

A loss of ENS neurons which leads to a failure of the LES to relax during swallowing. Esophageal dilation and aperistalsis are noted.

Question 6

What is diffuse esophageal spasms?

Answer 6

Uncoordinated contractions of normal amplitude that fail to propagate a bolus.

Presents with occasional pain and intermittent dysphagia

Question 7

What is nutcracker esophagus?

Answer 7

Coordinated contractions of an excessive amplitude which often present with pain

Question 8

What is a hiatal hernia?

Answer 8

When the stomach is pulled through the esophageal hiatus,, the opening in the diaphragm that the esophagus passes through from the thoracic to abdominal cavity