1. GUT PHYSIOLOGY Secretion 2 Dr. Jack Grider Rm 12-004 Sanger Hall
2009

2. Secretion: Gastroduodenal Junction

3. Secretions at the Gastroduodenal Junction
PANCREATIC:
-Serous component: Water and bicarbonate ion
-Protein component: pancreatic enzymes
BILIARY
-Serous component:Water and bicarbonate
-Protein & other: bile and related secretions
INTESTINAL:
-Serous: Water and electrolyte

4. Secretion:Pancreas Endocrine portion
insulin, somatostain, glucagon, pancreatic polypeptide
Exocrine portion
water, electrolyte, enzymes

5. Secretion: Exocrine Pancreas

6. Secretion: Exocrine Pancreas: serous

7. Secretion: Exocrine Pancreas: Protein
Storage in membrane bound zymogen granules
Storage as pro-enzymes
Trypsin inhibitor
Acidification of granule
Initial activation by enterokinase

8. Secretion: Exocrine Pancreas
Enterocyte
Gut Lumen
Pancreas

9. Secretion: Exocrine Pancreas
Proteases (75%)
endo & exo
trypsin
Amylase
Lipases
Phospholipase cholesterol ester hydrolyase
Other enzymes
nucleases, elastases, etc
Other proteins
procolipase, trypsin inhibitor

10. Secretion: Control Mechanisms
Neural
Hormonal
major
multiple hormones
Interactions

11. Secretion-Exocrine Pancreas: Neural Control

12. Secretion: Hormonal control
Secretin: water and Bicarbonate ion
CCK: enzyme component
-multiple stimulants of CCK
-interactions with neural control
PP & PYY: inhibitory control.

13. Secretion: Exocrine Pancreas Regulation by secretin

14. Secretion: Exocrine Pancreas Regulation by CCK6

15. Secretion: Exocrine Pancreas Regulation by CCK7

16. Secretion: Exocrine Pancreas PP & PYY

17. Secretion: Exocrine Pancreas

18. Secretion: Exocrine Pancreas

19. Secretion: Intestinal
Goblet cells: mucus
Duodenal Glands:
water & bicarbonate ion
Enterocyte
-villus migration (6 days)
-secretory cells in crytps
-water and chloride ion
-cystic fibrosis
transmembrane regulator
(CFTR channel)
and ClC2 channel
CFTR
Channel
Nutrient
Absorption
(Carriers)
Basolateral
Sodium
Pump
CFTR
Nutrient
carriers
Basolateral
Na pump

20. Secretion: Intestinal
ClC2
Cholera Tx

21. Secretion: Intestinal
Enteric neurons
from the
submucosal plexus
project all the way
to the tip of the
villus and innervate
mucosal cells.
Both sensory and
motor neurons
innervate the villus
and crypt cells

22. Secretion: Intestinal
Enteric neurons from
myenteric and submucosal
plexus, and extrinsic
neurons from the
sympathetic and
parasympathetic nervous
system regulate
secretomotor neurons (VIP
& Ach) and secretory
reflexes.
SSt, Opioid and SNS
inputs are inhibitory;
cholinergic are excitatory.

23. Secretion