Lecture 16: Endocrine Pancreas Flashcards

1
Q

what are the 4 musketeers of glycemic control

A
  • Liver
  • Adipose tissue
  • pancreas
  • muscle

all work together to regulate blood glucose levels

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

islands of endocrine cells in a sea of exocrine tissue

A

Islets of langerhans

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

main endocrine cell types

A
  • β cells (60%)
  • α cells (25%)
  • δ (10%)
  • gamma
  • epsilon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Beta cells secrete what hormones

A

insulin and Amylin

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

alpha cells secrete what hormone

A

glucagon

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

increased blood glucose casuses a decrease in __________ and an increase in ___________

A

decreased glucagon
increased insulin

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

decreased blood glucose levels cause a ________ in glucagon and a ______ in insulin

A

increased glucagon
decreased insulin

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

amylin is a hormone secreted by _____ that acts on the CNS to ……

A

B cells, suppresses appetite

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

delta cells secrete what hormone and what does it do

A

Somatostatin, it inhibits digestive function, inhiits α and β cells

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

gamma cells secrete what and what does it do

A

Pancreatic polypeptide, inhibits gastric juices, appetite and food intake

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

Epsilon cells secrete what and what does it do

A

Ghrelin, appetite stimulating hormone

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

C-peptide is a marker of _____ production and ______ cell function

A

Insulin production and β cell function

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

food intake leads to an increase in….

A
  • blood glucose concentration
  • increased blood amino acid concentration
  • increased GI hormones
  • increased parasympathetic stimulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

sympathetic stimulation (and epinephrine) block ____ cells via α-adrenergic stimulation

A

β cells

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

insulin secretion leads to…

A
  • decreased blood glucose
  • decreased blood fatty acids
  • decreased blood aas
  • increased protein synthesis
  • increased fuel storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

proinsulin is cleaved into ____ and _____

A

insulin and C-peptide

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

how does glucose stimulate insulin release?

A

excitation-secretion coupling in βcells

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

what are the steps of Excitation-secretion coupling in βcells

A
  • glucose depolarizes cell membrane
  • Glu enters via GLUT2
  • Glucose+PO43- –> Glucose-6-phosphate
  • G6P oxidation –> ATP
  • ATP closes K channel
  • decreased K flux depolarizes cell membrane
  • Voltage gated Ca channels open
  • Ca enters β cell
  • Ca triggers exocytossi of insulin vesicles
  • insulin is secreted into circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are some other humor factors that stimulate insulin release (besides glucose)

A
  • other sugars (fructose, mannose, ribose)
  • amino acids (leucine, arginine)
  • hormones (glucagon, secretin)
  • drugs (sulfonylurea, theophylline)
  • short chain fatty acids
  • ketone bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

carbohydrates ____ blood glucose and ____ storage

A

decrease blood glucose
increase storage

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

Lipids ____ blood fatty acids and ____ storage

A

decrease fatty acids
increase storage

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

proteins ____ blood amino acids and _____ storage

A

decrease, increase

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

GLUT____transports glucose across the BBB

A

GLUT 1

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

GLUT_____transports glucose in kidney and intestine

A

GLUT2

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

GLUT____transports glucose into neurons

A

GLUT3

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

GLUT____is an insulin-dependent glucose transporter in most other cells of the body: adipose tissue and resting muscle cells

A

GLUT4

27
Q

glucagon gets inhibited by…

A

high glucose
somatostatin

28
Q

glucagon is stimulated by…

A
  • low glucose
  • epinephrine β2
  • vagal stimulation
  • amino acids
29
Q

where is glucagon expressed?

A

in the liver, intestine, brain and pancreas α cells
produced as proglucagon

30
Q

proglucagon is proteolytically processed to yield_____ and______

A

glucagon + incretin(GLP1)

31
Q

GLP1 (incretin) is released from the intestine in reponse to…

A

high levels of glucose in the intestinal lumen

32
Q

incretin (GLP1) increases ________ release from beta cells

A

insulin

33
Q

glucagon mainly targets the ______ to stimulate ________ which increases plasma glucose levels

A

LIVER to stimulate hepatic glucose output

34
Q

glucagon opposes the effects of_______and increases gluconeogenesis and _________-

A

insulin, glycogenolysis

35
Q

What increases glucagon release

A
  • hypoglycemia
  • epinephrine, CCK, vagal stimulation, fasting, exercise
  • dietary protein (arginine) in absence of carbohydrates (if a meal is protein+carbs, no effect on glucagon)
36
Q

when CHO is a fuel source….. ________Increases and ___________ decreases

A

insulin increases
glucagon decreases

37
Q

when proteins are a fuel source… _______ increases in response to amino acids and ________ increases in response to low blood sugar

A

insulin, glucagon

38
Q

where does gluconeogenesis and glycogenolysis occur

A

liver

39
Q

what causes the release of somatostatin

A

high fat, carbs and protein rich means

reduces secretion of glucagon and insulin

40
Q

pancreatic polypeptide is secreted by what cells

A

γ(gamma)Cells

41
Q

what does pancreatic polypeptide do

A

inhibits secretion of pancreatic enzymes, hepatic glycogen and constriction of the gall bladder

42
Q

what stimulates the release of pancreatic polypeptide

A

fasting
intestinal hormones (cholecytokinin, secretin, gastrin)
stimulation of vagus nerve
ingesting protein

43
Q

what decreases pancreatic polypeptide

A

glucose and somatostatin

44
Q

what are some diabetogenic hormones besides glucagon

A
  • epinephrine
  • cortisol
  • growth hormone and IGF-1
  • pancreatic polypeptide

all generally OPPOSE INSULIN

45
Q

what is the role of the brain in hypothalamic control of fuel management

A

autonomic control of hormone release
sesnes nutrients and hormones associaated w/ nutrient levels

insulin, leptin, GLP-1 to drive appetite

46
Q

(within neural control of glucose) glucose detection occurs in the_______ Nucleus

A

Arcuate

47
Q

type I diabetes is _____ dependent and occurs due to a lack of _______ secretion from the pancreas

A

insulin dependent
insulin

48
Q

Type I DM has autoimmune effects….

A

T-cells destroy beta cells

49
Q

Type II diabetes is _____________ dependent, tissue resistance to insulin

A

non-insulin dependent

50
Q

what type of DM is often the result of diet/activity

A

type II

51
Q

acute symptoms of DM

A
  • elevated blood glucose
  • characteristics of post-absorptive state (like having just eaten a meal but all the time)
52
Q

Chronic effects of DM

A

retinopathy (cataracts in dogs)
pancreatic amyloidosis (cats)
neuropathy
nephropathy
cardiovascular disease
**KETOACIDOSIS

53
Q

occurs as a consequence of increased appetite

A

polyphagia

54
Q

occurs in attempt to compensate for dehydration

A

polydipsia

55
Q

hyperglycemia results form ….?

A

inadequate uptake of glucose into cells and an increased output of glucose from liver

56
Q

glucosuria

A

elevated glucose in glomerular filtrate is greater than what the tubular cells can reabsorb in the nephron

57
Q

what does the osmotic effect of glucosuria cause

A

draws additional water into filtrate = excess fluid is lost from the body resulting in dehydration

58
Q

hepatic use of fatty acid results in…?

A

ketosis

59
Q

ketone bodies in the blood disrupt blood pH, resulting in _______

A

metabolic acidosis

60
Q

what results in muscle wasting in DM

A

insulin deficiency causes increased protein degradation which causes muscle wasting + weight loss

61
Q

an excess of insulin results in….

A

hypoglycemia (low blood glucose)
effects are dangerous + manifest early in the brain
- loss of consciousness, depressed brain function
- weakness, fatigue, ataxia

62
Q

cats suffer nearly exclusively from type ____ diabetes?

A

type II

63
Q

insulin excess results in one of 3 ways….

A
  1. insulin overdose (give carbs)
  2. reactive hypoglycemia (in an extreme response to glucose, beta cells release too much insulin)
  3. islet tumor in dogs (excessive insulin release)
    - most common type of hypoglycemia in dogs
    - typically episodic
64
Q

treatment for DM in felines

A

insulin therapy every 12 hrs
diet therapy: low carbohydrate diet for life