Phys Johnson GI regulation

Question 1

4 major functions of the GI tract

Answer 1

motility
secretion
digestion
absorption

Question 2

SNS and PNS in GI tract. location of layers, who synapses there. 2 in wall, 2 outside for each.

Answer 2

Myenteric plexus, SNS & PNS
Submucosal plexus, SNS & PNS
vagus & pelvic nerves, PNS
sympathetic ganglia, SNS

Question 3

largest component of PNS runs in what structure?

Answer 3

Vagus

Question 4

Amount of PNS in vagus effarent vs affarent

Answer 4

25%, 75%

Question 5

vagovagal reflexes

Answer 5

those that have affarent and efferent

Question 6

how endocrine hormones travel wrt GI

Answer 6

in the blood, not lumen

Question 7

4 qualifications to call something a true hormone

Answer 7

1 secretion from a response
2 absence of innervation dependance
3 isolated
4 synthesized

Question 8

gastrin structure, 2 types

important part
is sulfation important?

Secreted from?

Answer 8

G34, G15 are big & little.

4 AAs at C-terminus are action site.
sulfation unimportant

produced in G-cells in the stomach

Question 9

CCK:
structure
sulfation
source

Answer 9

6 AAs identical to gastrin
always sulfated for CCK effect
I-cells of duod & jejunum

Question 10

difference in structure of gastrin and CCK

Answer 10

tyrosine in 6th (gastrin) or 7th (CCK) position from c-terminus
whether it’s sulfated

Question 11

secretin structure & importance of that structure

Answer 11

alpha-helical

entire sequence is essential, no active fragments

Question 12

location of gastrin secretion

Answer 12

antrum, some duodenum

Question 13

location of CCK secretion

Answer 13

duodenum, jejunum, some ileum

Question 14

location of secretin secretion

Answer 14

duodenum (requires acidic pH, so looses effect distally)

Question 15

location of GIP secretion

Answer 15

duodenum & jejunum

Question 16

location of motilin secretion

Answer 16

duodenum & jejunum

Question 17

Gastrin released by?

inhibited by?

Answer 17

protein, distention, nerves

acid

Question 18

CCK released by?

inhibited by?

Answer 18

protein, fat

-

Question 19

secretin released by?

inhibited by?

Answer 19

acid

-

Question 20

GIP released by?

inhibited by?

Answer 20

protein, fat, carbs

-

Question 21

motilin released by?

inhibited by?

Answer 21

nerves

-

Question 22

actions of gastrin

Answer 22

increase acid, mucosal growth

Question 23

CCK actions

Answer 23

bicarb increase, pancreatic enzyme secretion, gallbladder contraction, reduced gastric emptying, pancreatic growth

Question 24

Secretin actions

Answer 24

reduced acid
increased bicarbonate (major, pancreated & bile)
pancreatic growth

Question 25

GIP actions

Answer 25

reduced acid

increased insulin

Question 26

motilin actions

Answer 26

intestinal & gastric motility

Question 27

VIP actions

Answer 27

relaxes gut and sphincters via NO production

Question 28

Bombesin/GRP actions

Answer 28

stimulates gastrin release

Question 29

enkephalins

Answer 29

stim sm muscle contraction
inhibits intestinal secretion

(opposite of VIP)

Question 30

Somatostatin actions in stomach

released by
inhibited by

Answer 30

inhibits gastrin & hormone peptide release

released by acid
inhibited by vagus

Question 31

Histamine actions in stomach

released by

Answer 31

acid secretion

gastrin, Ach

Question 32

Zollinger-Ellison syndrome

Answer 32

overproduction of gastrin

ulcers, diarrhea, steatorrhea, high acid, inactivation of pancreatic lipase

Question 33

Werner-Morison Syndrome

Answer 33

overproduction of VIP -> high rates of intestinal secretion. diarrhea, metabolic acidosis, dehydration, hypokalemia

“VIPoma”