Anatomy Of Endocrine Pancreas

Front 1

what types of hormones do hormone cells of GI tract secrete?

Back 1

peptide and amine homrones

Front 2

where are the hormones of GI tract located?

Back 2

anywhere in the mucusa

Front 3

what are open HSC's?

Back 3

open into gut
may be responsive to gut contents

Front 4

what are closed HSCs

Back 4

deep to surface
receptive to changes in tissue envrionemt

Front 5

what are HSC's derived from?

Back 5

neural crest cells

Front 6

what are the two stains and two cell staining types in HSCs?

Back 6

argentaffin cells - silver
enterchromaffin cell - chromate salts

Front 7

how can you identify an HSC from other types of cell?

Back 7

contain basal granules

Front 8

what tumours can HSCs form?

Back 8

gastrinoma
insulinoma
vasoactive intestinal peptidoma

Front 9

what are the relations of the head of the pancreas?

Back 9

IVC
right renal artery and vein
left renal vein

Front 10

what are the realtions of the neck of the pancreas

Back 10

SMV and hepatic portal vein
SMa
pylorus of stomach

Front 11

what are the relations of the body of the pancreas?

Back 11

omental bursa
aorta
IVC

Front 12

what are the relations of the tail of the pancreas

Back 12

left adrenal glan
left kidney
spleen

Front 13

what is the blood supply of the pancreas

Back 13

superior and inferior pancreaticoduodenal arteries
great and dorsal branches of splenic artery

Front 14

describe development of pancreas

Back 14

dorsal and ventral pancreatic buds of gut
ventral moves to left side, brining bile duct
ventral forms head and uncinate process

Front 15

which cells differentiate into islet cells in pancreas formation?

Back 15

cells adjacent to the ducts

Front 16

describe the paracrine blood system / portal system in the pancreas

Back 16

blood goes to capillary bed of the islets
then goes to the capillary bed of the acinar ducts

Front 17

which area of the pancreas has particularly good blood supply

Back 17

islets

Front 18

how do exocrine and endocrine pancreas differ in their staining?

Back 18

exocrine: stains well
basal nuclei (blue) and enzymes stain pink
endocrine: does not stain as well

Front 19

how are the pancreatic islets distributed in pancresas

Back 19

fairly evenly, slightly more in tail, slighly less in body

Front 20

what do A cells secrete and how do they appear

Back 20

glucagon
granules: homogenous, dense spheres

Front 21

what do B cells secrete and how do they appear in stain?

Back 21

insulin and AMYLIN
crystals bound by loose membrane

Front 22

what are D cells and how do they appear in stain?

Back 22

secrete somatostatin
large spheres, heterogenous

Front 23

what do E cells produce?

Back 23

epislon cells
produce ghrelin which stimulates hunger

Front 24

what do PP / F cells produce?

Back 24

Pancreatic Peptide - self regulatory hormone

Front 25

how large is insulin and what is its half life?

Back 25

5800 Mw
half life 8-9 mins - free peptide so easily broken down by proteases in blood

Front 26

how many amino acids is insulin?

Back 26

86

Front 27

how many amino acids are all the insulin chains, describe them

Back 27

A 21
B 30
C 31 + 4 extra in proinsulin
A has intradisulphide bonds
A and B joined by disulphide bonds
C no bio activity, packaged with insulin

Front 28

how is insulin secreted by the cell?

Back 28

pre-proinsulin in RER cleaved and folded, proinsulin secreted in microvesicle
golgi converts pro to normal insulin
stores ready for secretion

Front 29

what is pre- in preproinsulin?

Back 29

a lipophillic marker molecule which indicates protein is for export

Front 30

how is pro insulin converted?

Back 30

PC1: cleaves at AA 32-33
PC2: cleaves at AA 65-66
CHP: removes 31, 32 from B chain
removes 64, 65 from C chain

Front 31

what is the order of cgains in insulin?

Back 31

B-C-A

Front 32

what happens to insulin when it has been converted to proinsulin?

Back 32

precipitates out
forms crystal with Zn
2 zinc: 6 insulin crystalloid core

Front 33

what is hyperproinsulinaema and what causes it?

Back 33

abnormal amounts of immature insulin
1) enzyme defect
2) type 2 diabetes

Front 34

what stimulates insulin release?

Back 34

nutrient stimulus - potentiated by incretins
nervous stimulation
pharmacological stimulation

Front 35

describe the nutrient stimuli for insulin release?

Back 35

glucose >5mM
taken up by B cells, metabolised, increased ATP/ADP ratio
causes closure of ATP dependant K channels
membrane depolarisation, Ca channels open
insulin exocytosis

Front 36

what potentiates nutrient stimuli of insulin release?

Back 36

incretins
GLP: glucagon like polypeptide
GIP: gastrin inhibiting peptide
increase response by 60%

Front 37

what drug classes increase insulin release?

Back 37

prandial glucose regulators and sulphonylureas
act on ATP dependant K channels

Front 38

describe effect of SNS on insulin release?

Back 38

b2 receptors increase release
a2 receptors decrease release
more a2 receptors on B cells so overall reduce insulin release

Front 39

describe effect of PSNS on insulin release

Back 39

increase insulin release

Front 40

what are the effects of insulin on liver?

Back 40

increase glycogen synthesis
decreased glycogenolysis
decreased gluconeogenesis

Front 41

what are the effects of insulin on adipose tissue?

Back 41

increased uptake of glucose via GlUT 4 receptors
decreased lypolysis
increased lypogenesis

Front 42

what are the effects of insulin on muscle tissue

Back 42

increased uptake of glucose via glut 4 receptors
increased protein synthesis
decreased protein breakdown

Front 43

what is the receptor for insulin?

Back 43

tyrosine kinase receptors

Front 44

how many amino acids is glucagon?

Back 44

29aa

Front 45

look at bit aboout glucagon and somatostatin

Back 45

d