Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

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
Rises in ATP _____ K+ channels
close
26
Sulfonylurea receptor ______ insulin secretion
increases - associated with ATP-dependent K+ channels - causes depol faster--> more Ca++ entry
27
What is sulfonylurea used for the treatment of?
Type 2 DM
28
The sulfonylurea receptor is targeted for the treatment of?
Type 2 DM
29
What is used as a tool for measuring fxn of beta cells and endogenous insulin secretion?
C peptide
30
What is used as a tool for measuring fxn of beta cells and endogenous insulin secretion?
C peptide
31
Release of insulin is?
Biphasic | -quick spike to get the ball rolling, then gradual increase in insulin secretion to take care of rest of meal
32
What phase of insulin is lost first in diabetics?
First phase (no initial spike)
33
What is an effect of insulin bound to its receptor?
- translocation of GLUT 4 to plasma membrane | - growth effects
34
What happens when insulin is bound to its receptor?
Autophosphorylates itself and phos other proteins --> internalized by target cell
35
What activates downregulation of the insulin receptor?
insulin (shuts itself off)
36
What stimulates AMP-kinase (AMPK) activation?
Muscle contractions
37
What is an alternative way to get GLUT 4 to the plasma membrane?
AMP-kinase (AMPK) activation | ---independent of insulin
38
Why don't you want to inject insulin when exercising?
Muscle contraction activates glucose entry into cell independent of insulin---> activate both pathways--> hypoglycemia
39
What factors stimulate insulin?
- increased glucose, aa, fatty acid and keto acid concentrations - glucagon - cortisol, GIP, K+ - sulfonylurea drugs - obesity
40
What factors inhibit insulin?
- decreased blood glucose - fasting - exercise - SOMATOSTATIN - alpha adrenergic agonists (NE) - diazoxide (K+ channel activator)----->treat hypoglycemia
41
What is the role of glucagon in insulin secretion?
it is inhibited by insulin but activates/modulates insulin action
42
What activates insulin secretion?
ACh, CCK, GLP-1
43
What inhibits insulin secretion?
Somatostatin
44
Describe insulin action on skeletal muscle
- + glycogen synthesis - increases glucose uptake - increases glycolysis and CHO oxidation - increases protein synthesis - decreases protein breakdown
45
Describe insulin actions on liver
- + glycogen syntehsis - increases glycolysis and CHO oidation - decreases gluconeogenesis - increases pyruvate oxidation - increases lipid storate, decreases oxidation - increases protein synth, decrease breakdown
46
Describe insulin actions on adipose tissue
- increased glucose uptake - increased glycolysis - decreased lipolysis - + uptake fatty acids
47
During insulin resistance, what happens to lipolysis in adipose tissue?
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
Describe Glucagon
stored in dense granules of alpha cells same family as secretin and GIP synthesized as preproglucagon
49
What is the major stimulator of glucagon secretion?
decreased blood glucose
50
What are minor stimulators of glucagon secretion?
increased arginine and alanine fasting CCK B adrenergic agonists ACh
51
What inhibits glucagon production and secretion?
Insulin Somatostatin Fatty acids Ketoacids
52
How does glucagon act on the liver to increase blood glucose?
increases gluconeogenesis (inhibits production of fructose-2,6-bisphosphate) increases glucogenolysis inhibits glycogen synthesis
53
What simultates lipolysis in adipose and muscle tissue?
glucagon
54
Conversion to mmol/L to mg/dL
mmol/L * 18
55
What is the overview of diabetes physiologically?
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
Describe development of Type 1 DM
Destruction of beta cells (autoimmune)--> sx when 80% destroyed increased blood glucose, fatty acids, ketoacids, AA DKA= decreased utilization of ketoacids
57
Hallmarks of Type 1 DM
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
Insulin replacement therapy is used for which DM?
Type 1
59
Drawbacks of insulin replacement
- painful and time consuming - lag between dosing and measurement - delayed absorption - poor control
60
Transplant B cells might be used for which DM
Type 1
61
What is the progressive exhaustion of active beta cells due to environmental factors?
insulin resistance
62
What is insulin resistance the hallmark for?
Type 2 DM
63
What environmental factors lead to insulin resistance?
sedentary lifestyle, malnutrition, obesity, chronic systemic inflammation
64
What is the mechanism of insulin resistance?
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
Hallmarks of Type 2 DM
- Reactive hyperinsulinemia | - Obesity-induced insulin resistance
66
Describe obesity-induced insulin resistance
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
Which DM is not as prone to ketoacidosis
Type 2
68
How can a person be Type 2 DM and nnon-obese?
decreased insulin release by pancreas independent of peripheral insulin resistance
69
What hormones stimulate insulin secretion, inhibit glucagon secretion and slow gastric emptying?
incretin hormones (reduced peak in Type 2 DM)
70
What are examples of incretin hormones?
GLP-1, GIP
71
What are some treamtents for Type 2 DM?
diet, exercise, sulfonylurea drugs, incretin analog, metformin (to sensitize to insulin), bariactric surgery, alpha glucosidase inhibitors to slow absorption of carbs
72
What is the age of onset of Type 1 DM?
peak in early childhood and adolescence
73
What is the age of onset of Type 2 DM?
post-puberty
74
Which DM has ketosis at onset
Type 1
75
Which DM has a strong tie to family hx
Type 2 DM
76
What is the pathophysiology of Type 1 DM?
autoimmune disease
77
What is the pathophysiology of Type 2 DM?
insulin resistance
78
Which DM is associated with Autoimmune Thyroid, Celiac disease and Addison's disease?
Type 1 DM
79
Which DM is associated with lipid abnormalities, PCOS and non-alcoholic fatty liver disease?
Type 2 DM
80
Where is GLUT 2 located?
insulin independent in liver and pancreas
81
Where is GLUT 4 located?
insulin dependent in muscle, adipose tissue, heart

GIGU (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions