Brainscape's Knowledge GenomeTM

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


See full index

LCRS > Endocrinology 4 - Insulin secretion > Flashcards

Endocrinology 4 - Insulin secretion Flashcards

1
Q

What is the hormone involved with lowering blood glucose?

A

Insulin.

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

What are the hormones involved with increasing blood glucose? (4)

A
  1. Glucagon.
  2. Somatotrophin.
  3. Catecholamines.
  4. Cortisol.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are possible complications of diabetes? (4)

A
  1. Diabetic retinopathy (affects vision).
  2. Nephropathy (kidney disease).
  3. Heart attacks.
  4. Stroke.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is glucose important?

A
  1. Very important energy substrate especially for CNS.

2. Very low blood glucose levels (below 2mM) could lead to coma and death.

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

What is 98% of the pancreas associated with? And the remaining 2%?

A

98% - Exocrine secretions via a duct to the small intestine.
2% - Endocrine = islets of Langerhans.

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

What are Islet of Langerhans made of? And what do each of the cells release? (3)

A
  1. Alpha - Glucagon.
  2. Beta - Insulin.
  3. Delta - Somatostatin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What increases insulin secretion? (6)

A
  1. Increased blood glucose.
  2. Certain AA.
  3. Certain gastrointestinal hormones (Glucagon Like Peptide).
  4. Glucagon.
  5. Parasympathetic activity.
  6. Beta cell receptors.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What decreases insulin secretion? (2)

A
  1. Somatostatin.

2. Sympathetic activity.

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

What are the effects of insulin? (5)

A
  1. Decreased lipolysis + increased lipogenesis.
  2. Increased glycogenesis.
  3. Increased glycolysis.
  4. Increased glucose transport into cells via GLUT4.
  5. Increased AA transport + increased protein synthesis + decreased protein breakdown.
    All the above decreases blood glucose levels.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What increases Glucagon secretion? (5)

A
  1. Decreased blood glucose levels.
  2. Certain AA.
  3. Certain gastrointestinal hormones.
  4. Sympathetic activity.
  5. Parasympathetic activity.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What decreases glucagon secretion? (2)

A
  1. Somatostatin.

2. Insulin.

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

What are the effects of glucagon? (3)

A
  1. Increased hepatic glycogenolysis.
  2. Increased lipolysis => increased gluconeogenesis.
  3. Increased AA transport into liver => increased gluconeogenesis.
    All the above increases blood glucose levels.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is glucose concentration detected by beta cells? (3 steps)

A
  1. Glucose enters beta cell via GLUT 2 (not insulin regulated).
  2. Converted to glucose-6-phosphate by glucokinase (rate determining step).
  3. The rate of glucose-6-phosphate production determines the rate of insulin production.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is insulin released by beta cells? (5 steps)

A
  1. Glucose enters the beta cell via GLUT 2.
  2. Converted to G6P by glucokinase.
  3. ATP porduced blocks ATP sensitive K+ channel on membrane.
  4. Opens voltage dependent Ca+ channel and Ca+ moves in.
  5. Exocytosis of stored insulin + production of further insulin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the structure of insulin?

A
  1. Constructed as pre-proinsulin - has three chains and signal peptide.
  2. C peptide and signal peptide are removed to produce insulin (2 chains).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How can you measure the endogenous insulin production of a person?

A

By measuring the amount of C peptide in the person as the molar ratio of insulin to C peptide is 1:1.

17
Q

What is the Incretin effect?

A

Food stimulates more insulin secretion if given orally rather than intravenously.

18
Q

What is Glucagon Like Peptide-1 (GLP-1)?

A
  1. It is a gut hormone that is secreted by L-cells in the gut in response to nutrients.
  2. It stimulates insulin production and suppresses glucagon.
  3. It increases the feeling of fullness and has a short half life.
19
Q

How can T2DM be treated?

A

DPPG-4 inhibitors prevent the degradation of GLP-1 = makes people feel full for longer.

20
Q

What is first phase insulin release?

A

When glucose given intravenously to a normal person they release the stored insulin (large amount) and carry on releasing for two hours.

21
Q

Do people with T2DM have first phase insulin release?

A

No. Insulin made later on.

22
Q

How is insulin detected by cells?

A
  1. Insulin binds to alpha subunit of insulin receptor.
  2. Beta subunit has conformational change and has a metabolic effect inside the cell on glucose, AA and FA.
  3. Also affects growth (mitogenic pathway).
23
Q

Is insulin resistance caused by the transmembrane protein not being able to recognize insulin?

A

No. It involves post receptor cytoplasmic elements of insulin function.

24
Q

What is Type 1 Diabetes Mellitus?

A
  1. Absolute insulin deficiency.

2. Elevated glucose where insulin is required to prevent ketoacidosis.

25
Q

What is Type 2 Diabetes Mellitus?

A
  1. Insulin resistance.
  2. More prevalent than T1DM and is a considerable health burden.
  3. It is defined in terms of glucose but can also be related to hypertension and dyslipidaemia.
  4. Has a significant genetic component although obesity can trigger the onset.
26
Q

What allows hormones in the pancreas to have an effect on adjacent cells? And what is this effect called?

A
  1. Paracrine effect.

2. Gap junctions allow this to happen.

27
Q

What is first phase insulin release important for?

A

It is important for switching off liver glucose production.

LCRS (22 decks)

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