GIT (exam 4)

Question 1

PNS is excitatory or inhibitory on the GIT?

Answer 1

excitatory

Question 2

SNS is excitatory or inhibitory on the GIT?

Answer 2

inhibitory

Question 3

Enteric system falls under what organization of the nervous system?

Answer 3

autonomic nervous system

Question 4

Intrinsic  Innervation (enteric nervous system) :
Myenteric plexus (Auerbach’s plexus)
controls?

Answer 4

Motility

think M and M for Myenteric and Motility

Question 5

Intrinsic  Innervation (enteric nervous system) :
Submucosal plexus ( Meissner’s plexus)
controls?

Answer 5

Secretion and blood flow

think S and S for submucosal and secretions

Question 6

what are the four “official” GI hormones?

Answer 6

gastrin
cholecystokinin
secretin
GIP

Question 7

When is gastrin released?

Answer 7

in response to a meal

Question 8

Upon stimulation gastrin causes what two reactions to take place?

Answer 8

Increases H+ secretion by gastric parietal cells

Stimulates growth of gastric mucosa – trophic action.

Question 9

Stimuli for gastrin secretion?

Answer 9

Secreted from G cells of the gastric antrum

Question 10

Gastrin is secreted from G cells of the gastric antrum in response to what three factors?

Answer 10

Small peptides and amino acids esp. phenylalanine and tryptophan (proteins)

Distension of stomach

Vagal stimulation

Question 11

What causes inhibition of Gastrin secretion?

Answer 11

Acid (hydrogen) in the lumen of the stomach inhibits gastrin release via negative feedback.

Question 12

Explain gastrin release and how the release is stopped?

Answer 12

gastrin is released in response to a meal, which increases H+ secretion in the stomach, the increase in acid creates neg. feedback to inhibit gastrin release.