Phys Johnson GI regulation Flashcards Preview

GI & Liver Fall 2013 CBD > Phys Johnson GI regulation > Flashcards

Flashcards in Phys Johnson GI regulation Deck (33):
1

4 major functions of the GI tract

motility
secretion
digestion
absorption

2

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

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

3

largest component of PNS runs in what structure?

Vagus

4

Amount of PNS in vagus effarent vs affarent

25%, 75%

5

vagovagal reflexes

those that have affarent and efferent

6

how endocrine hormones travel wrt GI

in the blood, not lumen

7

4 qualifications to call something a true hormone

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

8

gastrin structure, 2 types

important part
is sulfation important?

Secreted from?

G34, G15 are big & little.

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

produced in G-cells in the stomach

9

CCK:
structure
sulfation
source

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

10

difference in structure of gastrin and CCK

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

11

secretin structure & importance of that structure

alpha-helical
entire sequence is essential, no active fragments

12

location of gastrin secretion

antrum, some duodenum

13

location of CCK secretion

duodenum, jejunum, some ileum

14

location of secretin secretion

duodenum (requires acidic pH, so looses effect distally)

15

location of GIP secretion

duodenum & jejunum

16

location of motilin secretion

duodenum & jejunum

17

Gastrin released by?

inhibited by?

protein, distention, nerves

acid

18

CCK released by?

inhibited by?

protein, fat

-

19

secretin released by?

inhibited by?

acid

-

20

GIP released by?

inhibited by?

protein, fat, carbs

-

21

motilin released by?

inhibited by?

nerves

-

22

actions of gastrin

increase acid, mucosal growth

23

CCK actions

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

24

Secretin actions

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

25

GIP actions

reduced acid
increased insulin

26

motilin actions

intestinal & gastric motility

27

VIP actions

relaxes gut and sphincters via NO production

28

Bombesin/GRP actions

stimulates gastrin release

29

enkephalins

stim sm muscle contraction
inhibits intestinal secretion

(opposite of VIP)

30

Somatostatin actions in stomach

released by
inhibited by

inhibits gastrin & hormone peptide release

released by acid
inhibited by vagus

31

Histamine actions in stomach

released by

acid secretion

gastrin, Ach

32

Zollinger-Ellison syndrome

overproduction of gastrin

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

33

Werner-Morison Syndrome

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

"VIPoma"