Exocrine and endocrine pancreas

Question 1

exocrine pancreas overview

Answer 1

releases bicarbonate, Zymozans and enzymes

Question 2

endocrine pancreas overview

Answer 2

insulin, Glucagon, somatostatin, pancreatic polypeptide

Question 3

vast majority of pancreas=

Answer 3

exocrine

Question 4

10% of pancreas=

Answer 4

endocrine

Question 5

2 structures that make up the exocrine pancreas

Answer 5

intercalated ducts

Acinus

Question 6

what is an acinus

Answer 6

a cluster of cells that resembles a many lobed berry

Question 7

what structure leads directly away from the acinus

Answer 7

intercalated ducts

Question 8

what do the intercalated ducts feed into

Answer 8

intralobular ducts (eventually ending up in the pancreatic duct)

Question 9

what is present where the acinus meets the intercalated ducts

Answer 9

aciner cells

Question 10

what is the function of the intercalated ducts

Answer 10

to produce bicarbonate

Question 11

what is bicarbonate used for

Answer 11

to buffer the acidic environment to a pH optimal for enzymes to work

Question 12

what coverts CO2 and H2O to bicarbonate

Answer 12

Carbonic anhydrase

Question 13

what enzyme triggers the expulsion of bicarbonate

Answer 13

secretin

Question 14

what does secretin trigger inside the cell

Answer 14

ATP–> cyclic AMP

Question 15

what does cyclic AMP cause

Answer 15

expulsion of CL- and K+

Question 16

what does the activation of basolateral K+ channels do

Answer 16

hyperpolarises the cell

Question 17

what does cell polarisation favour

Answer 17

Apical CL- efflux through cAMP activated CL- channels (CFTR)

Question 18

how is CL- bought back into the cell

Answer 18

by the CL-/HCO3- exchange

Question 19

what enzyme is released for digestion of fat and protein

Answer 19

cholecytokinin (CCK)

Question 20

Where is cholecytokinin released from

Answer 20

I cells in the duodenum

Question 21

where does cholecytokin act and what is its role

Answer 21

in the pancreas so the appropriate enzymes that degrade fat are released

Question 22

what does secretin regulate

Answer 22

water homeostasis and secretions in stomach and duodenum

Question 23

what does secretin do in the intercalated ducts

Answer 23

makes the ducts function to produce bicarbonate

Question 24

where is secretin produced

Answer 24

S cells in the duodenum

Question 25

in cystic fibrosis where and what is the gene mutation

Answer 25

frameshift mutation in the cystic fibrosis conductance regulator (CFTR) gene

Question 26

what does cystic fibrosis lead to

Answer 26

viscous secretions that block exocrine movement of digestive enzymes

Question 27

what eventually happens to the exocrine pancreas in a patient with cystic fibrosis

Answer 27

digestive enzymes stay in the pancreas and start digesting the pancreas

Question 28

what enzyme can be given to aid digestion

Answer 28

Pancreatin

Question 29

what does pancreatin contain

Answer 29

amylase lipase protease

Question 30

what coating does pancreatin have

Answer 30

enteric coating

Question 31

4 cells of the endocrine pancreas

Answer 31

Beta cells Alpha cells Delta cells Epsilon cells

Question 32

what does alpha cells produce

Answer 32

glucagon

Question 33

what do beta cells produce

Answer 33

insulin

Question 34

what do delta cells produce

Answer 34

somatostatin

Question 35

what do epsilon cells produce

Answer 35

Ghrelin

Question 36

where is insulin encoded

Answer 36

chromosome 11

Question 37

where does insulin enter upon release from the beta cells

Answer 37

the portal circulation and is carried to the liver

Question 38

what happens to the proportion of insulin not broken in the liver

Answer 38

it is degraded in the kidneys

Question 39

2 forms of insulin

Answer 39

Hexameric form | Monomeric form

Question 40

active form of insulin=

Answer 40

monomeric form

Question 41

inactive form of insulin

Answer 41

Hexameric form

Question 42

shape of hexameric insulin

Answer 42

6 insulin molecules arranged in a three fold symmetry held together by a central zinc molecule forming histidine bonds

Question 43

shape of monomeric insulin

Answer 43

alpha and beta chains linked via disulphide bridges

Question 44

what is the original single polypeptide of insulin

Answer 44

preproinsulin

Question 45

what does preproinsulin produce after 1 peptide is cleaved

Answer 45

proinsulin

Question 46

when proinsulin matures what does it release

Answer 46

Central C-peptide

Question 47

what glucose receptor is on beta cells

Answer 47

GLUT2

Question 48

when does GLUT2 open

Answer 48

when glucose levels are high in surrounding cells

Question 49

what does the influx of glucose into the beta cell cause

Answer 49

increase ATP causing potassium channels open---> Depolarisation causing an influx of Calcium triggering vesicles holding hexameric insulin to release the insulin in monomeric form

Question 50

what glucose receptor is stored in vesicles in muscle and Fat cells

Answer 50

GLUT4

Question 51

what triggers the movement of GLUT4 to the cell

Answer 51

IRS-1 phosphorylation

Question 52

what can insulin be described by

Answer 52

glucose haemostat

Question 53

what is the principal organ of glucose homeostasis

Answer 53

the liver

Question 54

where is 90% of glucose derived from

Answer 54

liver glycogen and hepatic gluconeogenesis

Question 55

which organ is the main glucose consumer

Answer 55

the brain

Question 56

what is the brains uptake of glucose controlled by

Answer 56

Its OBLIGATORY (not controlled by insulin)

Question 57

what are other tissues glucose consumers

Answer 57

faculative

Question 58

glycogen synthesis

Answer 58

glycogenesis

Question 59

glycogen breakdown=

Answer 59

glycogenolysis

Question 60

glucose breakdown=

Answer 60

glycolysis

Question 61

what does somatostatin do

Answer 61

inhibits release of insulin and glucagon as well as exocrine pancreatic secretions

Question 62

when and why is somatostain released

Answer 62

after a meal to dampen the whole process down