Lecture 71 Flashcards

1
Q

_________ and _________ work together to regulate blood glucose after a meal and during fasting

A

insulin and glucose

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2
Q

_________ regulates blood glucose, FA, and AA metabolism

A

liver, adipose tissue, muscle

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3
Q

Pancreatic _________ synthesize hormones

A

islets of Langerhans

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4
Q

_________ is the major source of insulin inside the cell and makes up 65%

A

b cells

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5
Q

20 percent of this cell inside the pancreatic cell makes glucagon and most are around the outer rim of islet

A

a-cells

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6
Q

10 percent of this cell is interspersed b and a cells and it produces somatostatin

A

delta-cells

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7
Q

somatostain inhibits _________ cells?

A

a and b cells

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8
Q

endocrine pancreas is _________ percent of pancreatic mass

A

1-2 percent

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9
Q

some cells around the pancreatic islet release _________ to self regulate

A

pancreatic polypeptide

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10
Q

Hormones secreted into pancreatic veins and reach the liver via portal vein. The liver can control?

A

How much hormones from the pancreas reaches periphery

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11
Q

Central core of islet is _________

A

beta-cells

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12
Q

_________ connect a- cells to each other, B cells to each other and A to B cells

A

Gap junctions

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13
Q

Blood supply to the pancreas arranged so that venous blood from each cell type _________ other cell types

A

bathes

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14
Q

Small arteries enter islet core and capillaries are distributed throughout. Coverage at rim to form _________

A

veins

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15
Q

Islets innervated by adrenergic, cholinergic and _________ neurons.

A

peptidergic

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16
Q

first hormone isolated from animal sources, first to have structure determined and mechanism of action described

A

Insulin

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17
Q

Amino acid sequence varies by _________ but certain segments highly conserved within vertebrates

A

species

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18
Q

Segments of AA: location of disulfide bonds include end of A chain, c-terminal residues of _________

A

B-chain

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19
Q

_________ two species have the same sequence of insulin

A

dog and pig

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20
Q

usually injecting insulin of one species into another causes antibody formation- not a huge issue in _________ and _________ injected with insulin from other species

A

Dogs and cats

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21
Q

peptide hormone with 2 chains

A

A chain: 21 AA and B chain: 30 AA

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22
Q

_________ peptide hormone is longer and is biologically active

A

B chain

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23
Q

_________ are the 3 disulfide bridges

A

2 link A and B chain and 3rd is in A chain

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24
Q

Insuliin synthesis: Synthesized as _________ with four peptides

A

prehormones

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25
Q

_________ are the four peptides that comes with insulin synthesis?

A

Signal peptide bond cut out early, A+ B chains and C chain (comeding peptide)

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26
Q

Insulin synthesis: Proinsulin sent to ER, insulin folds and _________ forms

A

disulfide bridge

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27
Q

Insulin synthesis: Golgi packages into granules, proteases cut

A

C peptides

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28
Q

Insulin synthesis: Once golgi packages into granules and proteases cut C-peptudes, secretion happens via exocytosis and releases

A

Insulin and C-peptide together

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29
Q

Insulin metabolize din the liver creates _________ excreted in urine

A

Disulfide bond and A+ B chains

30
Q

most important stimulator of insulin secretion is

A

blood glucose

31
Q

1st step in insulin regulation: Transport of glucose into B cell by _________ via facilitated diffusion

A

GLUT 2 transporter

32
Q

2nd step in insulin regulation: Glucose immediately phosphorylated by _________ and ATP is the product

A

Glucokinase

33
Q

2nd step in insulin regulation continued: Phosphorylation starts signaling needed and prevents glucose from

A

leaving cell

34
Q

2nd step in insulin regulation: Glucose immediately phosphorylated by glucokinase and ATP is the product. ATP helps regulate _________?

A

insulin secretions

35
Q

3rd step in insulin regulation: ATP closed ATP-sensitive K channels _________ does this do?

A

depolarizes membrane

36
Q

4th step in insulin secretion: Depolarization opens voltage gated Ca channels- Ca flows into cell increasing _________?

A

Intracellular Ca

37
Q

5th step in insulin secretion: increase in Ca causes exocytosis of insulin granules into _________

A

Venous blood

38
Q

C-peptide is secreted in _________ amount to insulin

A

equal

39
Q

C peptide excreted is unchanged in the urine this means it is a useful tool to check _________?

A

B cell function

40
Q

Oral glucose causes greatest insulin response due to “ _________” effect

A

Incretin

41
Q

the incretin effect stimulates release of other hormones from SI such as

A

GIP and GLP-1 (additive effect to increase insulin)

42
Q

_________ are other substances that can stimulate insulin secretion?

A

AA, ketoacids FFA, K+, Ca, GIP, Ach, Glucagon

43
Q

Glucagon increases the release of glucose from stored glycogen. Blood glucose increase so _________

A

insulin needed

44
Q

_________ inhibits insulin secretion

A

fasting, exercise, somatostatin, leptin

45
Q

_________ stores insulin in peripheral cells

A

skeletal muscle and adipose tissue

46
Q

Insulin receptor is

A

tyrosine kinase

47
Q

Insulin receptor (Tyrosine kinase) have two _________ and two _________

A

Alpha subunits, beta subnitis

48
Q

The two alpha subunits of the insulin receptor are

A

extracellular

49
Q

The two beta subunits of insulin receptor span membrane and have _________ on intracellular side

A

Tyrosine kinase

50
Q

Mechanism of action of insulin in peripheral cell 1 : Insulin binds alpha subunits, causes conformational change and activates tyrosine kinase in _________

A

Beta subunits

51
Q

Mechanism of action of insulin in peripheral cell 1 : Tyrosine kinase _________ itself after activated B subunits

A

Phosphorylates

52
Q

Mechanism of action of insulin in peripheral cell 2: Tyrosine phosphorylates other proteins/enzymes involved in _________ of insulin

A

Physiological actions

53
Q

Mechanism of action of insulin in peripheral cell 2 : Tyrosine kinase phosphorylates other protein/enzymes including?

A

Phosphatases, phospholipases and G proteins

54
Q

Mechanism of action of insulin in peripheral cell 3 : Insulin receptor complex internalized by target cell to be

A

degraded, stored or recycled

55
Q

Mechanism of action of insulin in peripheral cell 3 : Insulin that is upregulated means it is being

A

recycled

56
Q

Action of insulin: When nutrients are available insulin makes sure those nutrients are _________

A

stored

57
Q

Glucose stored as _________ in muscles and liver

A

glycogen

58
Q

FFA stored as

A

adipose tissue

59
Q

proetin stored in?

A

muscles

60
Q

Insulin directly stimulates glucose uptake into muscles and fat but not _________

A

liver

61
Q

Liver is not dependent on insulin to take up _________

A

glucose

62
Q

some glucose transporters are _________ in order to work and some are not

A

insulin-dependent

63
Q

_________ are the insulin INDEPENDENT transporters

A

GLUT 1, GLUT 2 and GLUT 3

64
Q

This insulin independent transporter is found in brain and RBC.

A

GLUT 1

65
Q

This insulin independent transporter is found in liver and beta cells of pancreases

A

GLUT 2

66
Q

_________ can cause a decrease in insulin secretion causing chronic hyperglycemia

A

A decrease number of GLUT 2 transporters on B cells

67
Q

In the _________ insulin helps with phosphorylation of glucose and store it as glycogen

A

liver

68
Q

This insulin independent transport is found in the brain only

A

GLUT 3

69
Q

_________ are the insulin DEPENDENT transporters

A

GLUT 4

70
Q

GLUT 4 is found in fat, muscles and

A

brain

71
Q

Transport of glucose in intestines and kidneys IS NOT regulated by insulin but is _________ dependent

A

Na

72
Q

_________ is the glucose transport in the intestines that is Na dependent?

A

GLUT 5