Brainscape's Knowledge GenomeTM

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


See full index

Endocrinology > 4 - Insulin secretion and intermediary metabolism > Flashcards

4 - Insulin secretion and intermediary metabolism Flashcards

1
Q

How to remember what insulin does?

A

The eating hormone - it is released after you’ve eaten

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

What does insulin do in terms of blood [Glucose]?

A

DECREASES blood glucose concentration

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

What 4 things increase the concentration of glucose in the blood?

A
  • Glucagon
  • Catecholamines (hormones produced by adrenal glands)
  • Somatotrophin
  • Cortisol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define Type 1 Diabetes Mellitus.

A

Elevated glucose, were insulin is required to prevent ketoacidosis

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

Define Type 2 Diabetes Mellitus.

A

More common. It’s defined in terms of glucose but related to hypertension and dyslipidaemia.

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

How can glucose be monitored?

A

Capillary glucose monitoring

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

When does hypoglycaemia occur?

A

When there is an imbalance between diet, exercise and insulin

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

What is hypoglycaemia?

A

Low blood sugar.
Below 4-5mM

Below 2mM: unconscious, coma, death

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

What is the structure of the pancreas?

A

98% of the pancreas does exocrine secretions via a duct to the small intestine

2% of the pancreas are clumps of cells called Islets of Langerhans

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

What are the 3 types of cell in the islets of Langerhans?

A

alpha cells
beta cells
delta cells

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

What is the purpose of gap junctions between cells?

A

Allow small molecules to pass directly between cells

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

What are the purpose of tight junctions between cells?

A

To form small intercellular spaces

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

What do α-cells produce?

A

Glucagon

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

What do β-cells produce?

A

Insulin

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

What do δ-cells produce?

A

Somatostatin

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

What does insulin stimulate?

A

Growth and development

17
Q

What does somatostatin inhibit?

A

Insulin and Glucagon

18
Q

What does glucagon increase?

A

Blood glucose

19
Q

How does insulin decrease blood glucose?

A
  1. Increases glycogenesis (making glycogen from glucose)
  2. Increased glycolysis (breakdown of glucose)
  3. Increased transport of glucose into cells via GLUT4

= Decreased blood glucose

20
Q

How does insulin affect amino acids?

A

Insulin increases amino acid transport and increases protein synthesis

21
Q

How does insulin affect lipids?

A

Decreases lipolysis (breakdown of fats & lipids into fatty acids)

Increased lipogenesis (the metabolic formation of fat)

22
Q

What triggers make B-cells produce insulin?

A
  1. Increased blood glucose
  2. Glucagon from α cells.
  3. Certain gastrointestinal hormones
  4. Certain amino acids
  5. Parasympathetic activity (β-receptors)
23
Q

What triggers stop B-cells from making insulin?

A
  1. Somatostatin from δ-cells.

2. Sympathetic activity (α receptors)

24
Q

How does glucagon increase blood glucose?

A
  1. Increased amino acid transport into the liver
  2. Increased lipolysis
    1 & 2 = increased gluconeogenesis (making new glucose)
  3. Increased hepatic glycogenolysis (breaking down glycogen into glucose in the liver)

= Increased blood glucose

25
Q

How does a β-islet cell know when to make insulin?

What is the process?

A
  1. Glucose enters B-cell through GLUT2
  2. Glucokinase enzyme turns glucose into glucose-6-phosphate. This is the rate limiting step
  3. Metabolic pathways
  4. Insulin synthesis and release
26
Q

What is glucokinase also known as?

A

Hexokinase IV

‘The glucose sensor’

27
Q

What is proinsulin?

A

The precursor to insulin

28
Q

What is C-peptide?

A

A polypeptide that connects the A-chain of insulin to the B-chain.
It is removed before insulin is released.

29
Q

Slide 22

A

Look this up

30
Q

Which causes more insulin secretion, drinking glucose or giving it into a vein?

A

Drinking glucose causes more insulin secretion.

31
Q

What is the incretin effect?

A

Incretin is a hormone that stimulates insulin secretion in response to meals (food in the gastrointestinal tract)

32
Q

What is GLP-1?

What does it do?

A

Glucagon like peptide-1.

  • gut hormone
  • secreted in response to nutrients in gut
  • STIMULATES INSULIN
  • SUPPRESSES GLUCAGON
  • increases satiety (feeling of fullness)
33
Q

How do insulin receptors work? (Draw a picture)

A

It is a transmembrane receptor.

  1. Insulin attaches to α-subunits, this recognises the insulin.
  2. β-subunits span the membrane and are attached to the α-subunits.
  3. β-subunits pass the message onto the cytoplasm.
  4. Leads to phosphorylation of cell protein substrates.
34
Q

Which domains are found in the β-subunits?

A

Tyrosine kinase domains

35
Q

When glucose is metabolised into glucose-6-phosphate in the β-cells, ATP is produced, what does this ATP then do?

A

ATP blocks the ATP sensitive K+ channel.
This causes calcium to rush into the cell through voltage gated calcium channels.
Stored insulin is then released & new insulin production.

Endocrinology (18 decks)

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