Brainscape's Knowledge GenomeTM

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


See full index

Semester 4 (NME) > Diabetes Physiology > Flashcards

Diabetes Physiology Flashcards

1
Q

What mechanism does the glucose transporter use to get glucose into the cell?

A

Facilitated diffusion (no ATP needed)

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

What type of hormone are insulin, glucagon and somatostatin?

A

Peptide

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

Each glucose molecule produces how many acetyl-coA molecules?

A

2

So two cycles of the krebs cycle are needed per glucose molecule

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

Each molecule of glucose produces how many ATP molecules during aerobic respiration?

A

34

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

What causes fruity smelling breath in T1DM patients?

A

Ketones in the breath (Pair drops/ nail varnish remover)

Requires urgent hospital admission

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

What does a patient have to do to prepare for a fasting glucose test?

A

Drink nothing but water and eat nothing

For 8-10hours before the test

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

Which cells secrete GIP?

A

K cells in duodenum

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

Which cells secrete GLP-1?

A

L cells of ileum

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

What is the incretin effect?

A

Insulin response to oral glucose is greater than the response to IV glucose. GIP and GLP-1 peptide hormones are released from the duodenum and ileum respectively and act on Bcells in the pancreas (Decreased in T2DM)

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

What is the NICE recommended treatment for T2DM?

A

Metformin
Add sulfonylurea (or DPP-4 if high hypoglycemic risk)
Add thiazolidinedione or insulin
Increase insulin dose

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

Why do diabetic patients get dehydrated?

A

Because as glucose is lost in urine water is pulled out (so more water lost) osmotically

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

What is the effect on insulin on potassium?

A

Closes K+ channels
So K+ stuck inside the cell
Therefore depolarisation

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

Name 3 examples where testing HbA1c levels would not be accurate?

A

Anaemia
Pregnancy
Haemoglobinopathy

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

Which cells produce the hormone released during hypoglycaemia?

A

Alpha cells of pancreas

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

Which enzyme converts glucose to glucose-6-phosphate?

A

Hexokinase/ glucokinase

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

Injury to which cells in the pancreas can lead to type I diabetes?

A

Beta cells

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

Which of the glucose transporters are insulin dependent?

A

GLUT-4

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

Which substance is normally used to measure GFR?

A

Creatinine

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

What is the name for clusters of endocrine cells in the pancreas and how are the distributed?

A

Islets of langerhans

Scattered amoungst exocrine pancreatic acini

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

What % of pancreatic cells are endocrine?

A

1%

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

What are the 4 types of endocrine cell in the pancreas and what do they each release?

A

Alpha (20%)- Glucagon
Beta (70%)- Insulin
Delta (8%)- Somatostatin
F cells (2%)- Pancreatic polypetide

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

What is the most common endocrine cell in the pancreas and what does it release?

A

Beta cells

Insulin

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

What is glucagon and by what mechanism does it act on the cell?

A

A peptide hormone which increases blood sugar

Activates adenyl cyclase and increases cAMP

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

What metabolic processes are increased by high levels of glucagon?

A

Gluconeogenesis
Lipolysis
Glycogenolysis
Ketogenesis

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

What can inhibit insulin secretion?

A

Somatostatin

SNS stimulation

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

What is insulin and by what mechanism does it act on the cell?

A

A peptide hormone which tries to decrease blood sugar levels

Activates surface receptor which activates a tyrosine kinase (attaches phosphate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which hormone can inhibit glucagon secretion and where is that hormone secreted from?

A

Somatostatin

From Delta cells in pancreas

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

What is the role of F cells in the pancreas and what stimulates them?

A

Produce the hormone pancreatic polypeptide
(Regulates pancreatic enzyme release, GI absorption and gall bladder contraction)
- Stimulated by PNS/ protein rich meals

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

What stimulates pancreatic Bcells to release insulin? (4)

A

GIP/ GLP-1
High blood sugar levels
AA’s like arginine and leucine
PNS stimulation

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

Which receptors on pancreatic Beta cells detect blood glucose levels?

A

GLUT-2

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

Which glucose receptors are found mainly on neurons and in the placenta?

A

GLUT-3

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

Which of the glucose transports is insulin regulated?

A

GLUT-4

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

What is the GLUT-5 transporter and where is it found?

A

A fructose transporter

Found in small intestine enterocyte cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What controls how many GLUT-1 receptors are on the cell membrane?

A

Levels in cell membranes are increased by reduced glucose levels and decreased by increased glucose levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which glucose transport is bi-directional?

A

GLUT-2

Mainly renal, liver and pancreatic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Where are GLUT-1 transporters mainly distributed?

A

Is widely distributed in fetal tissues

In adult mainly in erythrocytes and BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Where is the GLUT-4 transporter mainly located?

A

Adipose and striated muscle

38
Q

How are GLUT-4 transporters activated?

A

Insulin binds to the insulin receptor in its dimeric form and activates the receptor’s tyrosine-kinase domain, a signal cascade occurs and then GLUT-4 is transporter to the membrane

39
Q

What happens to the glucose transporter when it contacts a glucose molecule?

A

Undergoes a conformation change

This allows glucose to pass in

40
Q

What metabolic processes are upregulated by increased levels of insulin?

A

Increased glucose uptake in cells (GLUT-4)
Glycogenosis (Storing glucose as glycogen)
Glycolysis (Breakdown of glucose to pyruvate)
Amino acid absorbtion/ protein synthesis/ triglyceride formation

41
Q

What is another name for somatostatin?

A

Growth hormone inhibting hormone (GH-IH)

42
Q

What is the function of the delta cells in the pancreas?

A

Release somatostatin

43
Q

What is the action of somatostatin?

A

Inhibits!
Insulin/ glucagon/ secretin/ CCK/ gastrin/ motilin

Uses G-coupled receptors

44
Q

What is the absorbtive state and what is it’s primary hormone?

A

Approx 4 hours after each meal
Where nutrient absorption occurs
Regulated by insulin (body is taking in and using glucose to manufacture proteins/ lipids)

45
Q

What process happen during the absorptive state?

A

Glycogenesis (Glucose stored as glycogen)
Glycolysis (Glucose broken down into AA’s)
AA’s to protein / triglyceride formation
Acetyl-CoA to FA’s / Pyruvate to AA’s

46
Q

What is the name of the first substance in the Kreb’s (citric acid cycle)

A

Acetyl-CoA

47
Q

What is the post-absorptive state?

A

When nutrients are not being absorbed so body uses up stores

48
Q

What key hormones regulate the post-absorptive state?

A

Glucagon/ GH/ adrenaline/ glucocorticoids

49
Q

What glucose related processes happen in the post-absorptive state?

A

Glycogenolysis (Glycogen to glucose)

Gluconeogenesis (AA/ glycerol to Pyruvate to glucose)

50
Q

What lipid/ protein related processes happen in the post-absorptive state?

A

Lipolysis- Triglycerides broken down
Lipid metabolism- FA’s converted to acetyl-coA
AA metabolism- AA’s converted to pyruvate

51
Q

What is the name for the process by which glucose is turned into pyruvate?

A

Glycolysis

52
Q

What is the name for the process by which glycogen is broken down to glucose?

A

Glycogenolysis

53
Q

What is the name for the process by which triglycerides are broken into FA’s and glycerol?

A

Lipolysis

54
Q

What is the name for the process by which by which pyruvate is converted into glucose?

A

Gluconeogenesis

55
Q

What happens to amino acids during the post-absorptive state?

A

Released from liver

Metabolised into pyruvate

56
Q

What is the electron transport chain?

A

NADH/ FADH2 are oxidised and loose their electrons, which join with H+ from the krebs cycle and oxygen to produce H2O

57
Q

Where does the process of the electron transport chain occur?

A

Mitochondria

58
Q

What initiates the Krebs/ citric acid/ TCA cycle?

A

Glucose is converted to 2 pyruvate molecules
Pyruvate is then oxidised to acetyl-coA
Acetyl-CoA is locked into krebs cycle

59
Q

What is the net result of the Krebs/ citric acid/ TCA cycle?

A

Acetyl-CoA cycling round gives off ATP/ NADH/ FADH which are used by the electron transport chain to gain energy

60
Q

Each molecule of glucose creates how many pyruvate molecules?

A

2

61
Q

Each molecule of glucose results in how many krebs cycles?

A

2

62
Q

What are the three ketone bodies?

A

Acetoacetate
Acetone
Betahydroxybutycate

63
Q

How are ketone bodies produced?

A

When lipids/ proteins are used to create Acetyl-CoA for the krebs cycle (instead of glucose being used)

64
Q

What happens to ketone bodies in circulation?

A

Liver CAN’T metabolise ketone bodies

So must circulate until taken up by peripheral cells and converted to Acetyl-CoA

65
Q

How does ketoacidosis develop?

A

Increased ketone body production = ketosis
Ketones disolve in solution producing H+, this causes a pH drop = Ketonemia
Eventually this exceeds buffering capacity= ketoacidosis

66
Q

Where is glycogen mainly stored in the body?

A

Liver and muscles

67
Q

What is the composition of the insulin molecule?

A

Two amino acid chains linked by a disulfide bond

68
Q

How is insulin secreted?

A

Preproinsulin is cleaved in the ER to proinsulin (three peptide chains). This is cleaved to insulin in the golgi apparatus and packaged into granules

69
Q

What is C peptide?

A

The peptide cleaved off when proinsulin becomes insulin

70
Q

What role can C-peptide play in patient monitoring?

A

Monitor how much endogenous insulin is being created in patients on insulin treatment

71
Q

10% of the secretion of Bcells are what?

A

Proinsulin and C peptide

72
Q

How long does insulin circulate in the blood and how does this come to an end?

A

Half life of about 6mins

Degraded by insulinase mainly in the liver (but also kidney and muscle)

73
Q

What is the composition of the insulin receptor?

A

4 (2 alpha/2beta) subunits linked by disulfide bonds

74
Q

Where does insulin bind on the insulin receptor? What happens after it binds?

A

To the alpha subunit

Receptor is phosphorylated, this acitvates tyrosine kinase which via messenger cascades results in GLUT 4 up-regulation

75
Q

Name 4 effects of insulin?

A

Increases cell uptake of glucose
Makes cell more permeable to AA’s/ ions
Increased cell metabolic rate

76
Q

What happens to muscle fibres when exercising (in relation to glucose)?

A

Muscle fibres become more permeable to glucose (even without insulin)

77
Q

Which transporters does glucose enter the Bcell via?

A

GLUT-2

78
Q

How does glucose stimulate insulin release in the Bcell?

A

Glucose in via GLUT-2 transporter,
Phosphorylated to gluc-6-phosphate by hexokinase
G-6-P is oxidised to ATP, which opens K+ATPase channels, causing calcium influx and fusion of insulin vesicles with the membrane

79
Q

Which agents inhibit B-cell release of insulin?

A

Somatostatin and noradrenaline

80
Q

Which hormones potentiate the release of insulin (when under glucose stimulation)?

A

GLP-1/ GIP

Gastrin/ secretin/ CCK can cause an anticipatory release whilst waiting for glucose/ AA absorption

81
Q

Growth hormone and cortisol are secreted more under which glucose linked conditions?

A

Hypoglycemia

they both inhibit cellular glucose utilization and promote fat use instead

82
Q

What effect does somatostatin have on glucagon and insulin?

A

Inhibits their secretion

83
Q

T1DM is an autoimmune disease charecterised by Bcell destruction whereas T2DM is…

A

A combination of peripheral resistance to insulin and an inadequate secretory response

84
Q

What are the main T-cells involved in the destruction of Bcells in T1DM?

A

Th1
CD8+
CTL’s

85
Q

How can HbA1c levels be used to predict diabetes severity?

A

Glycosated Hb can be a predictor of macrovascular complications later on

86
Q

What is the pathophysiology of diabetic retinopathy?

A

Hyperglycemia stimulates intracellular activation of Protein Kinase C

87
Q

What is the pathogenesis of macrovascular changes in diabetes?

A

Hyaline thickening of wall of arterioles and narrowing of lumen

88
Q

How do the membranes of diabetic patients differ to those in non-diabetics?

A

More leaky to protein

underlies diabetic nephropathy and retinopathy

89
Q

Which enzyme increases fatty acid levels in times of insulin deficiency?

A

Lipoprotein lipase

90
Q

What is the role of DPP-4?

A

Degrades incretins

Semester 4 (NME) (24 decks)

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