Endocrine pancreas and Glucose homeostasis Flashcards Preview

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Flashcards in Endocrine pancreas and Glucose homeostasis Deck (19)
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1

what are islets of Langerhans

clusters of ~1000 endocrine cells

2

how many islets of Langerhans are there in a human pancreas

1 million
(only 1-2% of pancreatic volume)

3

what are the different islet endocrine cell types

alpha-cells, beta-cells, delta-cells, PP-cells, epsilon-cell

4

what do alpha-cells in islet of Langerhans secrete

glucagon

5

what do beta-cells in islet of Langerhans secret

insulin

6

what do delta-cells in islet of Langerhans secret

somatostatin

7

what do PP-cells and epsilon-cells in islet of Langerhans secrete

PP-cells secrete pancreatic polypeptides
epsilon-cells secrete Ghrelin

8

what proportion of islet of Langerhans are each type of cell

beta-cells 55%, alpha-cells 38%, delta-cells <5%, PP-cells ~1%

9

what effect does fasting/exercise have on normoglycaemia

hypoglycaemia

10

what is the physiological response to hypoglycaemia and what does it result in

decrease insulin, increase glucagon
results in glucose production

11

what is the physiological response to hyperglycaemia and what does it result in

increase insulin, decrease glucagon
results in glycogen synthesis

12

what effect does feeding have on normoglycaemia

hyperglycaemia

13

how is lipid homeostasis affected by hypo- and hyperglycaemia

hypoglycaemia = hypolipidaemia
hyperglycaemia = hyperlipidaemia

14

how is lipid homeostasis affected by glucose production and glucose storage

glucose storage = lipid storage
glucose production = lipolysis

15

what does the beta-cell do in glucose homeostasis

beta-cell compensation

16

what does the beta-cell do in hyperglycaemia

beta-cell defected, relative to insulin demand

17

how does blood glucose affect glucagon secretion from alpha-cells

glucagon secretion inversely proportional to blood glucose

18

what effect does glucagon have on the liver

promotes hepatic glucose production, raising blood glucose

19

what happens to glucagon in T2DM

glucagon secretion is elevated in fed state, contributes to hyperglycaemia