1. PANCREAS ANATOMY esophagus stomach ductus choledocus pancreas duodenum
duct of
Santorini
duct of
Wirsung

3. PANCREATIC SECRETIONS
1. PROTEASES (70%)
Endopeptidases (trypsin, chymotrypsin, elastases)
Exopeptidases (carboxypeptidases)
trypsinogen trypsin activates all other precursors
enterokinase
(duct walls)
2. NUCLEASES (DNAase, RNAase)
3. PANCREATIC AMYLASE (hydrolyse starch and gl;ycogen)
4. PANCREATIC LIPASE (triglycerides fatty acids and glycerol)

4. REGULATION OF SECRETION
1. SECRETIN
food in
release of
release of secretin
secretion of
alkaline pH
stomach
stomach acid
into blood by
bicarbonate
(ideal for
into duodenum
duodenal cells
by duct cells
pancreatic enzymes)
2. PANCREOZYMIN (cholecystokinen)
amino acids and
release of pancreozymin
relase of pancreatic enzymes
fats in intestine
by intestinal mucosa
into the intestine
into blood
3. GASTRIN
food in stomach
gastrin secretion
release of pancreatic enzymes
into the intestine
by stomach mucosa
4. AUTONOMIC INNERVATION (vagus nerve)

5. PANCREAS (PANORAMIC) islet of Langerhans pancreatic acini islet of
pancreatic lobe
Langerhans BV

6. PANCREATIC SECRETORY DUCTS
LARGE SECRETORY DUCT
INTERLOBULAR DUCT
simple
cuboidal
epithelium
acinus
simple
columnar
epithelium

7. EXOCRINE PANCREAS pyramidal secretory acinus basal basophilia cell
(rough ER)
merocrine secretion
(exocytosis)
zymogen
granules
centro-
condensing
acinar
golgi
vacuoles
cells
vesicles
blood
vessel
intercalated
duct
rough
nerve
golgi
endoplasmic
apparatus
reticulum
interlobular
zymogen
duct
granules

8. INTERCALARY DUCTS AND CENTROACINAR CELLS

9. PANCREATIC EXOCRINE SECRETORY CELL
zymogen
granules
centroacinar
cell

10. CELL BIOLOGY OF PANCREATIC SECRETION
1. SYNTHESIS
2. SEGREGATION 14
C -leucine + tRNA
mRNA for
chymotrysinogen
ribosomes 14
C-amino-acyl tRNA
ribosomes
mRNA
polypeptide
chymotrysinogen
RER cisterna
6. DISCHARGE
3. INTRACELLULAR TRANSPORT
exocytosis
RER
transitional
elements
5. INTRACELLULAR
4. CONCENTRATION
STORAGE
golgi
zymogen
H2O
apparatus
granules
H2O
golgi vesicles
condensing vacuoles

11. EXPERIMENTAL METHODS IN CELL SECRETION
1. SUBCELLULAR FRACTIONATION
2. RADIOAUTOGRAPHY
(grind and find)
(cook and look)
developed silver grains
density
photographic
gradient
vesicles
centrifugation
emulsion
microsomes
(RER)
golgi
condensing
vacuoles
ultrathin
section
zymogen
granules
pancreatic
acinar cell
(3 mins)
(7 mins)
(80 mins)
cpm
cpm
cpm 14 C 14 C 14 C
leucine
leucine
leucine
RER
golgi
cond
zymogen
RER
golgi
cond
zymogen
RER
golgi
cond
zymogen
pulse chase

12. ISLET OF LANGERHANS “ ANTAGONISTIC HORMONES” alpha cell (glucagon)
vascular pole
(secretion by exocytosis)
acinus
beta cell
beta
cell
alpha
(insulin)
cell
fenestrated
capillary
blood
capillary
INSULIN- increases membrane
promotes glycogenesis
decrease blood glucose levels
permeability to glucose
GLUCAGON - promotes glycogenolysis
increases blood glucose levels
“ ANTAGONISTIC HORMONES”

13. ISLET OF LANGERHANS

14. ISLET OF LANGERHANS - TEM

15. STAINED ALPHA AND BETA CELLS
ALPHA CELLS
BETA CELLS