Exam 2: Pancreas Flashcards Preview

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Flashcards in Exam 2: Pancreas Deck (96)
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1
Q

5 hormones pancreas secretes

A
Insulin
Glucagon
Somatostatin
Pancreatic polypeptide
Ghrelin
2
Q

Endocrine cells of pancreas arranges in clusters called

A

Islets of Langerhans

3
Q

Islets of Langerhans make up ____% of pancreas

A

1-2%

4
Q

4 cell types in Islets

A

Alpha
Beta
Gamma
PP

5
Q

Alpha cells make up ___% and secrete ___

A

20% (outer rim)

Glucagon

6
Q

Beta cells make up ___% and secrete ____

A

65% (central core)

Insulin

7
Q

Gamma cells make up ___% and secrete ____

A

10% (interspersed)

Somatostatin

8
Q

PP cells make up __% and secrete ___

A

5%

Pancreatic polypeptide

9
Q

SNS innervation of islet cells is

A

Adrenergic

Peptidergic

10
Q

Para innervation of islet cells is

A

Cholinergic

Peptidergic

11
Q

Pre para fibers from _____ synapse with post cholinergic and peptidergic neurons in ____

A

Dorsal motor nucleus of vagus

Pancreatic ganglia

12
Q

Vagal stim via _____ stimulates release of ___

A

ACh and VIP

Insulin

13
Q

Pre sym cell bodies originate in ____ and synapse w/ post fibers in ____

A

Intermediolateral horn cells of cord

Paravertebral and celiac ganglia

14
Q

Sym nerve fibers cause stim of ___ and inhibition of ____ in pancreas

A

Glucagon

Insulin

15
Q

Insulin is synthesized and secreted by

A

B cells

16
Q

Preproinsulin

A

Signal peptide
A chain
B chain
C peptide

17
Q

Proinsulin

A

A chain
B chain
C peptide

18
Q

Proinsulin is shuttled to ER where

A

Disulfide bridges form

19
Q

In the golgi, proinsulin where

A

C peptide is removed

Secreted in granules

20
Q

Insulin is stored in

A

Secretory granules complexed with zinc

21
Q

Levels of C peptide accurately reflect ___ function

A

Beta cell

Used for type I diabetes patients

22
Q

Group of GI tract hormones that inc insulin release after eating

A

Incretins

23
Q

2 major incretins

A

GIP

GLP

24
Q

Incretins slow rate of intestinal absorption by

A

Slowing rate of emptying of stomach

May dec food intake

25
Q

Incretins inactivated by

A

Dipeptidyl peptidase 4 (DPP-4)

26
Q

DPP-4 inhibitors

A

Dec blood glucose by preventing breakdown of GIP and GLP

27
Q

FA and AA ____ insulin secretion

A

Stimulate

28
Q

Insulin receptor

A

Tetramer

Insulin binds to alpha subunits

29
Q

Insulin-receptor complex becomes internalized by

A

Endocytosis

30
Q

Once inside cell, insulin is either ___, ____, or ____

A

Degraded; stored; recycled

31
Q

Insulin can down regulate its own receptor by

A

Dec rate of synthesis

Inc rate of degradation

32
Q

Insulin ensures that excess nutrients are stored:

A

Glycogen — liver
Fat — adipose
Proteins — muscle

33
Q

Insulin decreases ____ blood concentrations

A

Glucose
FA and ketoacid
AA

34
Q

Insulin promotes __ uptake into cells

A

K+ and glucose

35
Q

Insulin also has a direct effect on ____ by stimulating ____

A

Hypothalamic satiety center

Ventromedial nucleus

36
Q

Insulin directs the insertion of ___ into cell membranes

A

GLUT4

37
Q

Insulin promotes formation of ____ in liver and muscle

A

Glycogen

38
Q

Insulin inhibits ____

A

Glycogenolysis and GNG

39
Q

Insulin in adipose

A

Stims fat deposition

Inhibits lipolysis

40
Q

Insulin in liver

A

Dec FA degradation — dec acetyl CoA

41
Q

How insulin dec blood AA

A

Inc AA and protein uptake

Inc protein synthesis and dec degradation

42
Q

Tissues that don’t need insulin for uptake

A
Brain
RBCs
Intestine
Cornea
Kidney
Liver
Exercising muscle
43
Q

GLUT2 is insulin ____

A

Independent

44
Q

Glucose transport into pancreatic beta cells is via

A

GLUT2

45
Q

Type 1 Diabetes

A

Insulin dependent

Destruction of B cells (autoimmune)

46
Q

Type 1 Diabetes effect on concentrations in blood

A

Inc blood glucose, FA, ketoacid, AA

Lose lean body mass and adipose

47
Q

Inc ketoacid in type 1 diabetes leads to

A

Metabolic acidosis (diabetic ketoacidosis)

48
Q

Other effects of Type 1 diabetes

A

Glucosuria

Hyperkalemia

49
Q

Hyperkalemia can lead to

A

Muscle flaccidity and weakness

50
Q

Type 2 diabetes

A

Non-insulin dependent

Insulin resistance

51
Q

Type 2 diabetes often occurs w/

A

Inflammation associated w/ obesity

52
Q

Inflammation causes adipocytes to secrete

A

Inflammatory mediators: IL-6 and TNF

53
Q

IL-6 and TNF induce signaling cascades that

A

Inhibit insulin receptors to function

54
Q

Type 2 diabetes causes by

A

Down regulation of insulin receptors

Insulin resistance

55
Q

Normal individuals concentration of glucose between meals

A

90 mg/dL

56
Q

A1C test reflects average blood glucose level for past

A

2-3 months

57
Q

A1C test measures

A

Percentage of Hemoglobin that is glycated

58
Q

Normal A1C levels

A

4-5.6 mg/dL

59
Q

Pre diabetic A1C level

A

5.7-6.4 mg/dL

60
Q

Diabetic A1C level

A

> 6.5 mg/dL

61
Q

Glucagon is synthesized and secreted by

A

Islet alpha cells

62
Q

Glucagon promotes mobilization and utilization of

A

CHO
Fats
AA

63
Q

Glucagon is synthesized as

A

Preproglucagon

64
Q

Glucagon is stored in

A

Dense granules

65
Q

Stim factors of glucagon

A
Fasting
Dec glucose and AA
CCK
Epi/NE
Ach
GIP
66
Q

Inhibitory factors of glucagon

A
Glucose
Insulin
Somatostatin
Inc FA and ketoacid
GLP-1
67
Q

Main site of action of glucagon

A

Liver

68
Q

Glucagon maintains _____ in fasting state

A

Blood glucose

69
Q

Glucagon stims liver to produce/secrete

A

Glucose and ketone bodies

70
Q

Glucagon effect on metabolism

A

Inc glycogenolysis
Inc GNG
Lipolysis

71
Q

Glucagon inc GNG by

A

Dec F26BP which dec PFK activity

72
Q

AA and lipolysis shunts substrates toward

A

GNG

73
Q

Glucagon inhibits formation of ____ from glucose

A

Glycogen

74
Q

Most important determinant of glucagon secretion

A

Concentration of glucose

75
Q

Plasma glucose >200 mg/dL, secretion of glucagon is

A

Maximally inhibited

76
Q

Dec blood glucose leads to ____ glucagon secretion

A

Stimulation

77
Q

Insulin ____ glucagon secretion

A

Inhibits

78
Q

Glucagon ____ insulin secretion

A

Stimulates

79
Q

FFA ____ glucagon secretion

A

Inhibit

80
Q

Glucagon secretion _____ by protein rich meal

A

Stimulated

81
Q

Digestion of protein rich foods stims release of CCK/GIP which

A

Stims pancreatic islet cells

both insulin and glucagon release

82
Q

Inc secretion of glucagon after protein meal serves to:

A

Prepare liver to dispose of AA by GNG

Signals liver to release glucose

83
Q

Somatostatin secretion stim by

A

Ingestion of all nutrients
Glucagon
B-adrenergic agonists

84
Q

Somatostatin secretion inhibited by

A

Insulin

85
Q

Somatostatin inhibits secretion of

A

Insulin and glucagon

86
Q

Somatostatin functions to

A

Modulate/limit responses of insulin and glucagon

87
Q

Function of pancreatic polypeptide

A

Self-regulate pancreas secretory activities

Effect hepatic glycogen levels and GI secretions

88
Q

Secretion of PP increased after

A

Protein meal
Fasting
Exercisa
Acute hypoglycemia

89
Q

Secretion of PP decreased by

A

Somatostatin

IV glucose

90
Q

Ghrelin secreted mainly by

A

Stomach mucosa between eating

91
Q

Ghrelin can be produced by other tissues:

A

Pancreas
Brain
Ovary
Adrenal cortex

92
Q

Ghrelin is released into blood and can cross ____ which affects ____

A

BBB

Hypothalamus

93
Q

Ghrelin ____ feelings of hunger

A

Inc

Stims hypothalamic neurons in appetite control centers

94
Q

Ghrelin effect on GI tract

A

Inc gastric acid secretion
Inc gastric motility
Inc gastric emptying

95
Q

Stim of ghrelin receptors on afferent neurons initiates

A

Vago-vagal reflexes and local enteric reflexes

96
Q

Only GI tract hormones that promotes food intake

A

Ghrelin