Brainscape's Knowledge GenomeTM

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


See full index

Endocrine System > Lecture 4 The Endocrine Pancreas 1&2 > Flashcards

Lecture 4 The Endocrine Pancreas 1&2 Flashcards

1
Q

Define Glucostatic Theory

A

Food intake is determined by blood glucose. As BG increases the drive the eat decreases

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

Define Lipostatic Theory

A

Food intake is determined by fat stores, as fat stores increase the drive to eat decreases. Leptin is a peptide hormone released by fat stores to depress feeding activity

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

Which energy output can the human body egulate

A

Mechanical work as it is voluntary

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

What is the absorptive state

A

Where ingested nutrients supply the energy needs of the body and the excess is stored (anabolic phase)

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

What is the Post-absorptive phase

A

Fasted State where we rely on body stores to provide energy (catabolic phase)

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

Why is the brain referred to as an obligatory glucose utiliser

A

Brain can only use glucose except in extra cases of starvation in which it uses ketones

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

What is the normal BG range

A

4.2-6.3mM (80-120mg/dl)

5mM

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

When is someone BG hypoglycaemic

A

<3mM

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

What are the 4 types of islet cells in the Islets of Langerhans

A

alpha cells produce GLUCAGON
beta cells produce INSULIN
delta cells produce SOMATOSTATIN
F cells produce pancreatic polypeptide

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

Describe how insulin goes from its active form to inactive

A

Preproinsulin
Proinsulin in ER
Proinsulin in cleaved in Golgi
Insulin and C-peptide

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

Excess glucose is stored as

A

Glycogen in liver

Triacylgycerides in liver and adipose tissue

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

Excess amino acids is stored as

A

Fat and form an energy source

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

Fatty acids are stored as

A

Triglycerides

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

Describe the mechanism of insulin secretion when glucose is abundant

A

Glucose enters cells through GLUT and metabolism increases
This increases [ATP] within the cell causing the KATP channel to close
Intracellular [K+ ] rises, depolarising the cell. Voltage-dependent Ca2+ channels open and trigger insulin vesicle exocytosis into the circulation.

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

Describe the mechanism of insulin secretion when glucose is low

A

ATP is low low so KATP channels are open so K+ ions flow out removing +ve charge from the cell and hyperpolarizing it, so that voltage-gated Ca2+ channels remain closed and insulin is not secreted.

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

Describe the primary action of Insulin

A
  1. Binds to tyrosine kinase receptors on the cell membrane of insulin-sensitive tissues to increase glucose uptake by these tissues
  2. Phosphorylates IRS
  3. Second messeger alter protein synthesis
  4. membrane transport modified
  5. Cell metabolism is changed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where is GLUT 2 located

A

plasma membrane of the liver, pancreatic, intestinal, kidney cells

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

Where is GLUT 4 located

A

cytoplasm of muscle and adipose tissue cells. When stimulated by insulin GLUT4 migrates to the membrane and is then able to transport glucose into the cell. When insulin stimulation stops, the GLUT-4 transporters return to the cytoplasmic pool

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

What tissues are insulin dependent

A

Muscle and Adipose tissue

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

What tissue isn’t insulin dependent

A

Liver

21
Q

Describe glucose uptake during the fed state in the liver

A

liver takes up glucose because insulin activates hexokinase which lowers [glucose]ic creating a gradient favouring glucose movement into the cells.

22
Q

Describe glucose movement during the fasted state

A

liver synthesises glucose via glycogenolysis and gluconeogenesis, increasing [glucose]ic creating a gradient favouring glucose movement out of the cells into the blood.

23
Q

What is the half-life of insulin

A

5 minutes

24
Q

What happens to the insulin bound receptors once insulin action is complete

A

insulin-bound receptors are internalised by endocytosis

25
Q

Name stimuli which increase insulin

A 
High Blood glucose
Amino acid
Glucagon
Incretin hormones
Vagal nerve activity
26
Q

Name stimuli which inhibit insulin

A

Low blood glucose
Somatostatin (GHIH)
Sympathetic
Stress e.g. hypoxia

27
Q

Between IV and oral glucose which would have the largest insulin response

A

• Oral loading of same amount of glucose   insulin by both direct effect on  cells and vagal stimulation of  cells, plus incretin effects

28
Q

What type of hormone is glucagon

A

Peptide hormone and produced by 1-cells of the pancreatic islets cells

29
Q

Glucagon mainly acts on what organ

A

Liver

30
Q

What is the plasma half-life of glucagon

A

5-10 minutes and degraded by liver

31
Q

Name the main actions of Glucagon

A

Opposes action of glucagon
Increased glycogenolysis
Increases gluconeogenesis
Formation of ketones from fatty acids

32
Q

Following a meal rich in proteins why is there an increase in insulin and glucagon

A

The rise in amino acids stimulates insulin secretion which promotes an increase in amino acid uptake and promotes decrease in plasma glucose  inappropriate and can lead to hypoglycaemia
• Rise in plasma amino acids also stimulates the secretion of glucagon which tends to promote an increase in plasma glucose

33
Q

Stimuli that promote glucagon release

A
  • Low blood glucose
  • High amino acids to prevent hypoglycaemia
  • Sympathetic innervation and adrenaline B2 effects
  • Cortisol
  • Stress e.g. exercise, infection
34
Q

Stimuli that inhibit glucagon release

A
  • Glucose
  • FFA
  • Insulin
  • Somatostatin
35
Q

Describe the parasympathetic stimulation of Islet cells

A

Insulin increase as well as glucagon in anticipation of digestion

36
Q

Describe the sympathetic stimulation of islet cells

A

Increase in glucagon, epinephrine and inhibition of insulin

37
Q

Name hormones that regulate muscle glycogenlysis

A

Epinephrine

38
Q

Name hormones that regulate liver glycogenolysis

A

Glucagon

Epinphrine

39
Q

Name hormones that regulate Gluconeogenesis

A

Glucagon

40
Q

Name hormones that regulate inhibition of glucose uptake

A

Cortisol and GH

41
Q

Name hormones that regulate lipolysis

A

Epinphrine

42
Q

Name hormones that regulate protein catabolism

A

Cortisol

43
Q

Somatostatin in secreted by what cell

A

D-cells of the pancreas and hypothalamus (GHIH)

44
Q

What is the main actions of Somatostatin

A

Inhibit activity in the GI tracts
Slow down absorption of nutrients to prevent exaggerated peaks in plasma concentration
Supress release of insulin and glucagon in paracrine fashion
GHIH it inhibits secretion of GH from the anterior pituitary

45
Q

What is the effect of exercise on blood glucose

A

Entry of glucose into skeletal muscle is increased. Even in the absence of insulin
Muscle sensitivity to insulin increases which causes an increase in insulin independent GLUT 4 transporters

46
Q

What is the molecular weight of glucose

A

180

47
Q

How do you work out the blood glucose in mM

A

Divide blood glucose after fasting by (180/18)

48
Q

Name complications of diabetes

A
  • Hyperglycaemia
  • Retinopathy
  • Neuropathy
  • Nephropathy
  • Cardiovascular Disease

Endocrine System (26 decks)

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