Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GIGU > Endocrine Pancreas > Flashcards

Endocrine Pancreas Flashcards

1
Q

What products does the ENDOCRINE pancreas secrete?

A

insulin, glucagon, somatostatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What fxn does the endocrine pancreas have?

A

regulates lipid, carb and AA metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe Islets of Langerhans

A

cells of endocrine pancreas

  • only 1-2% of pancreatic mass
  • 2500 cells/islet
  • adren, cholin, peptid neurons (para, symp, paracrine)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What cells are in Islets of Langerhans?

A

alpha, beta, delta, F cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What cells makes up 60-65% of islet?

A

beta cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What cell is centrally located in an islet?

A

beta cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What cell secretes insulin and C peptide?

A

beta cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What cell is peripherally located in an islet?

A

alpha cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What cell makes up 20% of an islet?

A

alpha cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What cell secretes glucagon?

A

alpha cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What cell makes up 5% of the islets?

A

delta cell

- interspersed between alpha and beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What cell secretes somatostatin?

A

delta cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What cell is neuronal in appearance and sends “dendrite” like processes to beta cells?

A

delta cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the fxn of pancreatic polypeptides?

A

satiety signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What cells communicate through gap junctions?

A

a-a
b-b
b-a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the blood flow through islets of langerhans

A

Blood comes up through the middle and spreads out to periphery
- first to B cells then a cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does blood flow utilize insulin and glucagon?

A

Blood flows first through B cells which carries insulin to alpha cells in the blood—–> stops the release of glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe paracrine actions in islets

A

—>works reverse of blood flow

alpha cells communicate with beta cells to inhibit further insulin release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a major anabolic hormone?

A

insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the major stimulatory factor of insulin secretion?

A

glucose (CHO- and/or protein secretion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the pathway to make insulin

A

Preproinsulin (signal peptide with C peptide, no disulfide bonds)–> Proinsulin (no signal peptide)–> insulin and C peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What can be used as a marker of endogenous insulin secretion?

A

C peptide (high insulin= high C peptide)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is GLUT 4 translocated to the membrane?

A

Insulin binds to receptor (IRS)–> proteins phos to + or - downstream pathways (PI3K, MAP)–> translocation of vesicles with GLUT 4 to membrane–> glucose enters via facilitated diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe steps of insulin release

A

1: Glucose enters cell via GLUT 2
2: phos by glucokinase
3: G6P oxidized–> ATP generation
4: ATP closes inward rectifying K channel
5: PM depolarized
6: + voltage-gated Ca++ channels
7: Ca++ enterse cell
8: + mobilization of insulin and C peptide vesicles to PM–>exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Rises in ATP _____ K+ channels

A

close

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sulfonylurea receptor ______ insulin secretion

A

increases

  • associated with ATP-dependent K+ channels
  • causes depol faster–> more Ca++ entry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is sulfonylurea used for the treatment of?

A

Type 2 DM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The sulfonylurea receptor is targeted for the treatment of?

A

Type 2 DM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is used as a tool for measuring fxn of beta cells and endogenous insulin secretion?

A

C peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is used as a tool for measuring fxn of beta cells and endogenous insulin secretion?

A

C peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Release of insulin is?

A

Biphasic

-quick spike to get the ball rolling, then gradual increase in insulin secretion to take care of rest of meal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What phase of insulin is lost first in diabetics?

A

First phase (no initial spike)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is an effect of insulin bound to its receptor?

A
  • translocation of GLUT 4 to plasma membrane

- growth effects

34
Q

What happens when insulin is bound to its receptor?

A

Autophosphorylates itself and phos other proteins

–> internalized by target cell

35
Q

What activates downregulation of the insulin receptor?

A

insulin (shuts itself off)

36
Q

What stimulates AMP-kinase (AMPK) activation?

A

Muscle contractions

37
Q

What is an alternative way to get GLUT 4 to the plasma membrane?

A

AMP-kinase (AMPK) activation

—independent of insulin

38
Q

Why don’t you want to inject insulin when exercising?

A

Muscle contraction activates glucose entry into cell independent of insulin—> activate both pathways–> hypoglycemia

39
Q

What factors stimulate insulin?

A
  • increased glucose, aa, fatty acid and keto acid concentrations
  • glucagon
  • cortisol, GIP, K+
  • sulfonylurea drugs
  • obesity
40
Q

What factors inhibit insulin?

A
  • decreased blood glucose
  • fasting
  • exercise
  • SOMATOSTATIN
  • alpha adrenergic agonists (NE)
  • diazoxide (K+ channel activator)—–>treat hypoglycemia
41
Q

What is the role of glucagon in insulin secretion?

A

it is inhibited by insulin but activates/modulates insulin action

42
Q

What activates insulin secretion?

A

ACh, CCK, GLP-1

43
Q

What inhibits insulin secretion?

A

Somatostatin

44
Q

Describe insulin action on skeletal muscle

A
    • glycogen synthesis
  • increases glucose uptake
  • increases glycolysis and CHO oxidation
  • increases protein synthesis
  • decreases protein breakdown
45
Q

Describe insulin actions on liver

A
    • glycogen syntehsis
  • increases glycolysis and CHO oidation
  • decreases gluconeogenesis
  • increases pyruvate oxidation
  • increases lipid storate, decreases oxidation
  • increases protein synth, decrease breakdown
46
Q

Describe insulin actions on adipose tissue

A
  • increased glucose uptake
  • increased glycolysis
  • decreased lipolysis
    • uptake fatty acids
47
Q

During insulin resistance, what happens to lipolysis in adipose tissue?

A

Your body is not sensing insulin as a signal to decrease lipolysis, so it is constantly occurring—> release of fatty acids–> high levels in type 2 DM

48
Q

Describe Glucagon

A

stored in dense granules of alpha cells

same family as secretin and GIP

synthesized as preproglucagon

49
Q

What is the major stimulator of glucagon secretion?

A

decreased blood glucose

50
Q

What are minor stimulators of glucagon secretion?

A

increased arginine and alanine

fasting

CCK

B adrenergic agonists

ACh

51
Q

What inhibits glucagon production and secretion?

A

Insulin

Somatostatin

Fatty acids

Ketoacids

52
Q

How does glucagon act on the liver to increase blood glucose?

A

increases gluconeogenesis (inhibits production of fructose-2,6-bisphosphate)

increases glucogenolysis

inhibits glycogen synthesis

53
Q

What simultates lipolysis in adipose and muscle tissue?

A

glucagon

54
Q

Conversion to mmol/L to mg/dL

A

mmol/L * 18

55
Q

What is the overview of diabetes physiologically?

A

Liver is producing glucose because it is deficient or resistant to insulin–> too much in blood–> kidneys are getting rid of glucose in urine–> glucose takes water with it–> volume depletion

ALSO:
increased protein catabolism in muscle and lipolysis in adipose tissue–> ketogenesis in liver–> ketoacidosis–> coma

56
Q

Describe development of Type 1 DM

A

Destruction of beta cells (autoimmune)–> sx when 80% destroyed

increased blood glucose, fatty acids, ketoacids, AA

DKA= decreased utilization of ketoacids

57
Q

Hallmarks of Type 1 DM

A

Hyperkalemia (K+ out of cells)–> intracellular low due to lack of insulin effect on Na+/K+ ATPase
————-> plasma may be normal, but total K+ low due to polyuria and dehydration

Osmotic diuresis/Glucosuria
–> increased filtered lload of glucose leads to more water and glucose in urine (impairs kidney resorption)
=====polyuria, polydipsia

58
Q

Insulin replacement therapy is used for which DM?

A

Type 1

59
Q

Drawbacks of insulin replacement

A
  • painful and time consuming
  • lag between dosing and measurement
  • delayed absorption
  • poor control
60
Q

Transplant B cells might be used for which DM

A

Type 1

61
Q

What is the progressive exhaustion of active beta cells due to environmental factors?

A

insulin resistance

62
Q

What is insulin resistance the hallmark for?

A

Type 2 DM

63
Q

What environmental factors lead to insulin resistance?

A

sedentary lifestyle, malnutrition, obesity, chronic systemic inflammation

64
Q

What is the mechanism of insulin resistance?

A

Need more baseline insulin to try and maintain glucose balance
—->exaggerated insulin response to meal, takes a lot longer to get down to baseline glucose

65
Q

Hallmarks of Type 2 DM

A
  • Reactive hyperinsulinemia

- Obesity-induced insulin resistance

66
Q

Describe obesity-induced insulin resistance

A

Decreased GLUT 4 uptake of glucose in response to insulin (SM impairment)

Decreased ability of insulin to repress hepatic glucose production

Inability of insulin to repress adipose tissue uptake and lipolysis

67
Q

Which DM is not as prone to ketoacidosis

A

Type 2

68
Q

How can a person be Type 2 DM and nnon-obese?

A

decreased insulin release by pancreas independent of peripheral insulin resistance

69
Q

What hormones stimulate insulin secretion, inhibit glucagon secretion and slow gastric emptying?

A

incretin hormones (reduced peak in Type 2 DM)

70
Q

What are examples of incretin hormones?

A

GLP-1, GIP

71
Q

What are some treamtents for Type 2 DM?

A

diet, exercise, sulfonylurea drugs, incretin analog, metformin (to sensitize to insulin), bariactric surgery, alpha glucosidase inhibitors to slow absorption of carbs

72
Q

What is the age of onset of Type 1 DM?

A

peak in early childhood and adolescence

73
Q

What is the age of onset of Type 2 DM?

A

post-puberty

74
Q

Which DM has ketosis at onset

A

Type 1

75
Q

Which DM has a strong tie to family hx

A

Type 2 DM

76
Q

What is the pathophysiology of Type 1 DM?

A

autoimmune disease

77
Q

What is the pathophysiology of Type 2 DM?

A

insulin resistance

78
Q

Which DM is associated with Autoimmune Thyroid, Celiac disease and Addison’s disease?

A

Type 1 DM

79
Q

Which DM is associated with lipid abnormalities, PCOS and non-alcoholic fatty liver disease?

A

Type 2 DM

80
Q

Where is GLUT 2 located?

A

insulin independent in liver and pancreas

81
Q

Where is GLUT 4 located?

A

insulin dependent in muscle, adipose tissue, heart

GIGU (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions