L76: Pancreas Flashcards Preview

FHB - Endocrinology (by Richie) > L76: Pancreas > Flashcards

Flashcards in L76: Pancreas Deck (37)
1

What's the ""islets of langerhans"

Endocrine pancreas - 3 major cell types. Minority of pancreatic mass.

2

Exocrine pancreas

Majority of cells. Digestive enzymes and secretions.

3

What do epsilon cells secrete?

Ghrelin

4

What do delta cells secrete?

Somatostatin

5

What do beta cells secrete?

Insulin

6

What do PP cells secrete?

Pancreatic polypeptide

7

What does pancreatic polypeptide do?

inhibits acinar cells via paracrine action

8

What is amylin?

Synergizes with insulin. Can create plaques if built up in stressed out B-cells

9

C-peptide half life?

35 min. Good indicator of pancreatic function.

10

Good indicator of pancreatic function

C-peptide

11

Why is cleavage of C-peptide critical?

exposes end of insulin chain that interacts with receptor

12

What glucose transporter is on the Beta-cell?

Glut2

13

What is the "glucose sensor" of the beta-cell?

Glucokinase

14

What senses ATP from glucose metabolism in B-cell, promoting closure of K+ channels?

SUR subunit

15

What kind of drugs act on SUR to close the K+ channel, and promote insulin release?

Sulfonylurea drugs

16

What promotes vesicle (of insulin) release at B-cell?

Ca++ influx

17

What inhibits insulin release at B-cell?

ACh

18

What potentiates insulin release at B-cell?

FFA/aa's (increase ATP through oxidation), and GLP1 (Incretin)

19

Describe the nature of insulin release

biphasic

20

Insulin binds what type of receptor?

Tyrosine kinase

21

Which GLUT is insulin dependent

GLUT4

22

What two pathways does the insulin receptor promote

1. Increase GLUT4 installation
2. Increase growth/mitogenetic actions

23

What 4 factors does pro-glucagon consist of?

GRPP, glucagon, GLP-1, GLP-2

24

What happen to GRPP-Glucagon in the pancreatic islet cell?

Cleaved to GRPP + glucagon (Active peptides)

25

T/F: glucagon phosphorylates the bifunctional enzyme

True, it phosphorylates the enzyme, conferring PHOSPHATASE activity. Dephosphorylation of downstream enzymes promotes gluconeogenesis.

26

T/F: insulin dephosphorylates the bifunctional enzyme

T: insulin dephosphorylates the bifunctional enzyme, conferring KINASE activity. Phosphorylation of the downstream enzymes promotes glycolysis

27

What inhibits hepatic ketogenesis

insulin

28

Can insulin inhibit glucagon secretion at the alpha-cell?

Yes

29

Can glucagon inhibit insulin secretion at the b-cell?

no

30

What promotes hepatic ketogenesis?

Catecholamines, glucagon

31

SS14 (delta cells)

suppresses insulin release

32

Synergistic with insulin regulation of blood glucose

amylin

33

Contributes to amyloid formation in beta-cell

amylin

34

Inverse correlation with ghrelin and

obesity

35

What two hormones have a permissive effect on gluconeogenesis and lipolysis?

GH and cortisol

36

Ghrelin has what effect on hypothalamus?

Promotes appetite

37

What happens if GH is present, but not insulin?

"in the absence of insulin, GH is elevated but cannot stimulate hepatic IGF-1. Result: direct glucose mobilization effects of GH, but no cellular proliferation effects of IGF-1. Also, no negative feedback to GH."