GI Regulation

Question 1

What are the four functions of the GI tract?

Answer 1

Motility
Secretion
Digestion
Absorption

Question 2

Parasympathetic stimulation has what effect on the gut?

Answer 2

stimulates gut motility

Question 3

Sympathetic stimulation has what effect on the gut?

Answer 3

inhibits gut motility

Question 4

Vagus nerve innervates what parts of the GI tract?

Answer 4

Mouth through the transverse colon

Question 5

Vagus nerve provides parasympathetic innervation

Answer 5

ok

Question 6

Pelvic nerve supplies parasympathetic innervation to the descending colon.

Answer 6

ok

Question 7

What are the two layers of longitudinal muscle in the gut?

Answer 7

circular and longitudinal muscle

Question 8

Which of these two smooth muscle layers is closest to the mucosa (inner lining of the stomach)

Answer 8

Circular

Question 9

When circular muscle contract, the gut….

Answer 9

shortens

Question 10

When longitudinal muscles contract, the gut…

Answer 10

lengthens

Question 11

Vagus nerve in the GI is what percent afferent?

Answer 11

75%

Question 12

Sympathetic nervous system

Answer 12

innervates muscles/ secretory systems

Question 13

Vagal- vagal reflex

Answer 13

Both the afferent and efferent responses are vagus nerve controlled

Question 14

Enteric nervous system…

Answer 14

Primarily made up of the elements of the two plexi (myenteric and submucosal).

Question 15

Digestive tract is stimulated by both parasympathetic and sympathetic nervous systems

Answer 15

truth

Question 16

Primary parasympathetic innervation is via what?

Answer 16

Vagus Nerve

Question 17

Gastrin

Answer 17

17 amino acid peptide with all of its activity in the C-Terminus (four amino acids on the end- Trp, Met, Asp, Phe)

Question 18

What chemical modifications on gastrin prevent it from being degraded by the amino and carboxy peptides as it moves through the liver?

Answer 18

• Pyroglutamate
• NH2 group

Remember, gastrin is by the GI tract so it goes into the portal circulation which means its going to pass through the liver.

Question 19

CCK

Answer 19

Cholecystokinin

Question 20

When a hormone ends in -in, it does what

Answer 20

stimulates

Question 21

Cholecystokinin does what

Answer 21

stimulates gallbladder, stimulates pancreas, slows gastric motility, relaxes sphincter of oddi

Question 22

What happens when you de-sulfate the tyrosine residue of CCK

Answer 22

It becomes gastrin pretty much…has gastrin like activity

Question 23

What is the definition of a physiological dose of a GI hormone

Answer 23

a dose that doesn’t increase blood levels anymore than what you would see in response to a meal.

Question 24

6 sections of the GI tract according to Johnson’s hormone diagram

Answer 24

• Fundus, Antrum, Duodenum, Jejunum, Ileum, Colon

Question 25

Gastrin secreted in what segments

Answer 25

Antrum and Duodenum mostly

Question 26

CCK secreted where?

Answer 26

Duodenum, Jejunum, ileum to an extent

Question 27

Secretin secreted where?

Answer 27

Duodenum

Question 28

GIP

Answer 28

Duodenum and Jejunum

Question 29

know the releasers slide

Answer 29

ok

Question 30

Gastrin does what

Answer 30

Acid secretion and mucosal growth

Question 31

CCK does what?

Answer 31

Pancreatic bicarb secretion, pancreatic enzyme secretion, Gallbladder contraction (major), pancreatic growth, ALSO inhibits gastric emptying (amajor)

Question 32

Secretin does what

Answer 32

Pancreatic bicarb secretion (major) Bile bicarb secretion Pancreatic growth Inhibits acid secretion (probably not significantly in man)

Question 33

GIP does what?

Answer 33

Insulin release

Question 34

Motilin does what

Answer 34

Gastric motility and Intestinal motility

Question 35

What are the three neurocrines?

Answer 35

- VIP (vasoactive intestinal peptide) - Bombesin - Enkephaline

Question 36

VIP does what?

Answer 36

relaxes sphincters, relaxes gut circular muscle, stimulates intestinal secretion, stimulates pancreatic secretion

Question 37

Bombesin does what?

Answer 37

Also called Gastrin releasing Peptide (GRP) | It is the vagal mediator for gastrin release

Question 38

Enkephaline does what?

Answer 38

Stimulates smooth muscle contraction and inhibits secretion

Question 39

Know somatostatin and histamine as the two paracrines

Answer 39

ok

Question 40

Pt presents with duodenal ulcer, diarrhea, and steatorrhea. What endocrine cell tumor of the GI might tey have?

Answer 40

Gastrinoma (zollinger-ellison syndrome)

Question 41

What is zollinger ellison syndrome?

Answer 41

Tumor that leads to the over production of gastrin which leads to the over production of acid

Question 42

Werner Morison Syndrome?

Answer 42

Also called pancreatic cholera Over production of VIP Clinically presents as diarrhea, metabolic acidosis, dehydration, hypokalemia,