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Physiology > Pancreatic Hormones > Flashcards

Flashcards in Pancreatic Hormones Deck (79):
1

What is the exocrine function of the pancreas?

Digestive gland/enzymatic secretion

2

What is the endocrine function of the pancreas?

Hormone synthesis (insulin)

3

Where do the exocrine products of the pancreas go?

Through the duct system into the duodenum

4

What is the innervation of the islets of Langerhans?

Symp and para

5

What are the islet cells types?

Alpha
Beta
Delta
Epsilon
PP

6

What do alpha cells secrete? (2)

Glucagon
Proglucagon

7

What do beta cells secrete? (5)

Insulin
C-peptide
Proinsulin
Islet amyloid polypeptide
GABA

8

What do delta cells secrete?

Somatostatin

9

What do epsilon cells secrete?

Ghrelin

10

What do PP/F cells secrete?

Pancreatic polypeptide

11

What type of hormone is insulin?

Peptide

12

How is insulin made?

Translated as proproinsulin

Cleaved to proinsulin, then packaged into secretory granules with enzyme to turn into insulin

13

What links the alpha and beta chains of preproinsulin?

disulfide bonds

14

What is C peptide?

Fragment of preproinsulin

15

What is the half-life of insulin?

3-5 minutes

16

The release of insulin is what? (constant, variable etc)

Pulsatile and periodic

17

What are the three ways that the release of insulin is regulated?

Neural
Hormonal
Nutrient/ion

18

What is the nerve that innervates the islet cells?

Vagus

19

What is the most potent stimulator of insulin release?

Glucose

20

What ion's influx is induced by glucose?

Ca

21

What does increased ATP/ADP ratio close in a cell? What does this cause?

Inhibits K channel in cells

This causes depolarization

22

What happens when cells are depolarized from the K channel closing?

Ca rushes in, causing insulin secretion

23

What are the receptors that stimulate islet cells? What is the neurotransmitter? G protein?

M3 receptors
ACh
Gq

24

What is main the amplifier of insulin secretion?

Glucagon-like peptide (GLP1)

25

What is the effect of catecholamines on insulin secretion?

Increases secretion if bind Beta

Decreases if binds alpha

26

What is the effect of somatostatin on insulin?

Inhibits release

27

What is the insulin receptor like?

Transcellular Y kinase

Mitogenic and metabolic

28

Can glucose diffuse across a cell membrane? If not, how does it get in the cell?

No, uses energy dependent transport

29

What is the effect of insulin receptor signalling?

Promotes translocation of receptors of glucose to the cell membrane

30

Where is GLUT 1 found? Function?

All tissues
Basal uptake

31

Where is GLUT 2 found? Function?

Pancreatic beta cells
Insulin release

32

Where is GLUT 3 found? Function?

All tissues
Neuronal uptake

33

Where is GLUT 4 found? Function?

Skeletal muscle, fat
Insulin mediated uptake

34

Where is GLUT 5 found? Function?

Gut, kidney
FRUCTOSE uptake

35

Which GLUT transporter is regulated by insulin

4

36

Which GLUT transporter is on the surface of pancreatic B cells?

2

37

What is the effect of insulin of glycogen synthesis?

Increases

38

What is the effect of insulin on glycogen breakdown?

Inhibits

39

What is the effect of insulin on protein synthesis?

Increases

40

What is the effect of insulin on triglyceride synthesis?

Increases

41

What is the effect of insulin on glycogenolysis?

Inhibits

42

What is the effect of insulin on ketogenesis?

Inhibits

43

What is the effect of insulin on gluconeogenesis?

Inhibits

44

What is the effect of insulin on amino acid uptake in muscle?

INcreases

45

What is the effect of insulin on glycogen synthesis (3)?

1. Increases glucose uptake
2. Increases glycogen synthase activity
3. Inhibits glycogen phosphorylase

46

What are the three effect of insulin on triglyceride storage?

1. Promotes fFA uptake
2. Promotes esterification of fFA
3. Inhibits lipolysis

47

Which cells secrete glucagon?

Alpha cells, and in the gut

48

What is the effect of glucose on glucagon secretion?

Inhibits

49

What is the effect of catecholamines of glucagon?

Promote glucagon release

50

What type of innervation stimulates glucagon release (symp or para)?

Both symp and para

51

What is the effect of FA of glycogen release?

Suppresses

52

What type of receptors does glucagon bind to?

G protein

53

What is the effect of glucagon on glucose output? Ketone body output?

Promotes both

54

What is the effect of glucagon on gluconeogenesis? Insulin?

Glucagon increases
Insulin decreases

55

What is the effect of glucagon on glycogenolysis? Insulin?

Glucagon increases
Insulin decreases

56

What is the effect of glucagon on glycolysis? Insulin?

Glucagon decreases
Insulin increases

57

What are the three hormones that promote Triglyceride breakdown in the absence of insulin?

Epi
Cort
Glucagon

58

Where is the glucagon gene expressed?

Gut and pancreas

59

GLP1 is secreted when?

in response to glucose, lipids, and parasymp stimualatino

60

What is the effect of GLP1?

Promotes the production and secretion of both insulin and somatostatin

61

GLP1 promotes the growth of what cells?

Beta cells

62

What degrades GLP1?

Dipeptidyl peptidase 4 (DPP-4)

63

What produces amoylin (IAPP)? When is it released?

Beta cells
Released by same stimulators of insulin

64

What is the function of Amylin?

Decreases glucagon secretion and GI motility

65

What pancreatic cells produce somatostatin?

Delta cells

66

When is somatostatin produced?

In response to insulin release stimuli

67

What is the function of somatostatin? What is this mediated through?

Inhibits insulin secretion in a paracrine fashion through SSTR-5

68

What cells produce pancreatic polypeptide? What causes its release?

F or PP cells in the pancreas

Released with neuronal control

69

What is the function of pancreatic polypeptide?

Regulated exocrine function of the pancreas

70

What pancreatic cells produce Ghrelin?

Epsilon cells

71

What is the function of Ghrelin? (3)

Induces gastric emptying, acid secretion, and increases appetite

72

What allows intestinal cells to express GLP1 and GLP2? (What enzyme)

Express prohormone convertase 1

73

GLP1 is secreted in response to what? (3)

Glucose, lipids, and parasymp stimulation

74

What is the effect of GLP1 on the growth of beta cells?

Increases

75

What degrades GLP1?

DPP-4

76

What do catecholamines do to insulin secretion?

Decrease

77

What does beta stimulation do to insulin secretion?

Increase

78

What does alpha stimulation do to insulin secretion?

Decrease

79

What do somatostatin do to insulin secretion?

Decrease