Brainscape's Knowledge GenomeTM

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


See full index

BRS Y1 > Week 4- Glucose Homeostasis > Flashcards

Week 4- Glucose Homeostasis Flashcards

1
Q

What blood glucose level causes cerebral function to be impaired?

A

Below 4-5 mmol/L

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

What blood glucose level causes coma?

A

< 2 mmol/L

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

What is the most prevalent type of diabetes mellitus?

A

Type 2

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

What type of structure is the pancreas gland?

A

Retroperitoneal

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

What are the 3 types of cells found in islets of Langerhans? What hormone do each of these cells produce?

A

Alpha-glucagon
Beta-insulin
Delta-somatostatin

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

What are the actions of insulin?

A

Reduces blood glucose, encourages growth and development

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

What is special about GLUT 2?

A

It is not insulin sensitive

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

How is insulin secreted from beta cells?

A

Glucose enters beta cell via GLUT 2

Glucose 6 phosphate generated from glucose via glucokinase enzyme (rate limiting step)

ATP generated

ATP inhibits potassium channel

Potassium level in cell rises

Intracellular potassium opens calcium ion channel

Influx of calcium causes stored insulin release and synthesis of more insulin

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

How is insulin synthesised?

A

The precursor proinsulin undergoes proteolytic cleavage to form C peptide and insulin

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

What is C peptide a marker of?

A

Endogenous insulin

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

What hormone is involved in the incretin effect?

A

Glucagon like peptide-1 (GLP 1)

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

What happens to levels of GLP-1 in type 2 diabetics?

A

Levels are lower

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

What does the insulin receptor compose of?

A

An alpha subunit (extracellular domain that insulin binds to) and a beta subunit

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

What do most cells of the pancreas do?

A

Generate exocrine secretions to the small intestine

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

What is insulin inhibited by?

A

Somatostatin

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

What is glucagon inhibited by?

A

Somatostatin

17
Q

What does glucagon do?

A

Increases blood glucose

18
Q

What stimulates beta cells to produce insulin?

A

Increased blood glucose
Some amino acids from food that has been eaten
Some GI hormones
PNS activity

19
Q

What inhibits beta cells from producing insulin?

A 
SNS activity (although minor stimulation still occurs)
Delta cell production of somatostatin
20
Q

How does insulin effect blood glucose?

A

It increases glycogenesis, glycolysis and glucose transport into cells via GLUT4

Overall this reduces blood glucose

21
Q

How does insulin effect lipid levels?

A

It decreases lipolysis

It increases lipogensis

22
Q

How does insulin effect protein levels?

A

It increases amino acid transport

It increases protein synthesis

23
Q

What stimulates alpha cells to produce glucagon?

A 
Reduction in blood glucose 
Some amino acids via diet
Some GI hormones 
SNS activity
PNS activity
24
Q

What inhibits alpha cell production of glucagon?

A

Beta cell secretion of insulin

25
Q

What physiological changes does glucagon cause?

A

Mainly increase in hepatic glycogenolysis

Increase in amino acid transport to the liver and lipolysis both of which increase gluconeogenesis

26
Q

What is the rate limiting step in beta cells during insulin secretion? What is the name of the enzyme involved?

A

Conversion of glucose to glucose 6 phosphate

Enzyme involved is gluokinase

27
Q

What is the incretin effect?

A

The phenomenon wherein plasma insulin levels increase much more significantly when glucose is given orally compared to intravenously due to the effects of GI hormones (mainly GLP-1)

28
Q

What is GLP 1 and what are its effects?

A

Its a gut hormone secreted in response to certain gut nutrients, it stimulates insulin and surpresses glucagon, increases satiety (feeling of fullness)

29
Q

What is a special property of GLP-1?

A

It has a short half life due to rapid degeneration from enzyme dipeptidyl peptidase 4

30
Q

Why may GLP-1 be used in the treatment of diabetes and which type?

A

T2DM, it helps promote satiety which can help with weight loss commonly associated with T2DM and usually type 2s have lower GLP-1 anyways

31
Q

How is first phase insulin release different in those with T2DM compared to normal people and why?

A

There is no spike in insulin levels after first phase glucose release in T2DM as they dont have as much stored insulin. They therefore have to synthesise new insulin which results in slower restoration of blood glucose that is also incomplete

32
Q

What happens to the insulin receptor when insulin binds to it?

A

There is a conformational change in the tyrosine kinase domains of the beta subunits

BRS Y1 (52 decks)

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