Brainscape's Knowledge GenomeTM

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


See full index

Endocrinology > Pancreas Endocrinology - Lecture 2 > Flashcards

Pancreas Endocrinology - Lecture 2 Flashcards

1
Q

Is the secretion of insulin and glucagon dependant on long term regulation or hour to hour regulation?

A

Hour to hour regulation.

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

What are Islets of Langerhans?

A

Small clusters of cells scattered throughout the body of the pancreas. They make up the cells of the ENDOCRINE pancreas.

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

Pancreatic cells/tissues are made up of exocrine and endocrine cells. Which of these two make up 98% of pancreatic cells?

A

Exocrine cells.

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

What do the EXOCRINE cells of the pancreas produce and secrete?

A

Digestive ENZYMES and BICARBONATE.

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

Name the 4 ENDOCRINE hormones the pancreas produces.

A

Glucagon, Insulin, Amylin, Somatostatin.

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

What do the Alpha and Beta cells of the Endocrine pancreas secrete?

A

Alpha cells - Glucagon

Beta cells - Insulin and Amylin

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

Are there more alpha or beta cells in the endocrine pancreas?

A

Beta cells

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

Are Islets of Langerhans ENDOCRINE or EXOCRINE?

A

Endocrine

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

Name the 4 types of cells that make up the Islets of Langerhans.

A

Alpha, Beta, D and F cells

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

Of the 4 types of Islets of Langerhans cells which make up the endocrine pancreas, which of these make up the largest percentage?

A

Beta cells which make up 75% and they produce and secrete insulin and amylin.

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

Is Insulin an Alpha or Beta cell of the endocrine pancreas?

A

Beta cell

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

Is Insulin a peptide or lipid hormone?

A

Peptide

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

Does Insulin combine with a membrane receptor or a receptor located inside the cell?

A

Insulin combines with a membrane receptor located on the surface of the cell.

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

Does insulin use GPCR or Receptor Tyrosine Kinase (RTK) to initiate its activity?

A

Receptor Tyrosine Kinase which phosphorylates proteins.

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

Is Insulin synthesised as an active hormone or a prohormone?

A

It is synthesised as a prohormone.

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

How many amino acids are in an Insulin chain?

A

51 amino acids.

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

When an Insulin receptor at the cell membrane is activated, what what type of proteins does it phosphorylate?

A

IRS, or Insulin-receptor substrates

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

What type of bonds are present when the peptide chain of Insulin is in its prohormone stage?

A

Disulphide bonds

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

Is Glucagon an Alpha or Beta cell of the endocrine pancreas?

A

Alpha cell

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

How many amino acids make up a chain of a Glucagon hormone?

A

29 amino acids

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

Does Insulin INCREASE or DECREASE blood glucose levels?

A

DECREASE

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

Does Glucagon INCREASE or DECREASE blood glucose levels

A

INCREASE, to prevent hypoglycaemia

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

What is metabolism controlled by?

A

The Insulin/Glucagon Ratio

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

Define the FED state

A

The period following a meal and is characterised by by a high level of nutrients in the blood, the most important being Glucose

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

Define FASTED state

A

The willing abstinence or reduction of some or all food, drink or both.

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

During the FED state, which hormone dominates?

A

Insulin

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

During the FAST state, which hormone dominates?

A

Glucagon

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

Name a major stimulus for Insulin release.

A

When plasma glucose concentrations are greater than 100mg/dL. This happens when in the Fed state.

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

During a meal, do Insulin levels go UP or DOWN?

A

Insulin levels go up

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

During a meal, do Glucagon levels go UP or DOWN?

A

Glucagon levels goes DOWN

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

Which organs are the primary targets for insulin?

A

Liver, adipose tissue and skeletal muscle.

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

Does parasympathetic activity INCREASE or DECREASE insulin release?

A

INCREASES insulin release

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

Do adipose tissue and RESTING skeletal muscle require insulin for glucose intake? What happens to the GLUT4 transporters on the cell membrane in the absence of insulin?

A

Yes, both require insulin in order to intake glucose into the cell. When insulin is not present, the GLUT4 transporters which are sitting on the cell membrane are withdrawn and stored in the cytoplasmic vesicles (example of membrane recycling)

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

When skeletal muscle is working, is GLUT4 expression increased or decreased and is it dependant of insulin?

A

GLUT4 expression is increased independently of insulin.

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

What happens to GLUT4 receptors in the FED state?

A

The insulin signals the cell to insert GLUT4 transporters to the cell membrane from the vesicles.

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

Is EXERCISING skeletal muscle dependant on insulin to uptake glucose? Describe what happens when a skeletal muscle is exercising.

A

No it is not. When the muscle contracts, GLUT4 transporters are inserted into the membrane even in the absence of insulin, and the glucose uptake increases.

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

Is glucose uptake in liver cells (hepatocytes) dependant on insulin?

A

Glucose uptake in hepatocytes is NOT DIRECTLY dependant on insulin but it is influenced by it. GUT2 transporters are always present on cell membranes in Liver cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What happens to glucose in the FED state in liver cells?

A

Glucose enters the liver cell (hepatocyte)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What happens to glucose in the FASTED state in liver cells?

A

The Liver cell (hepatocyte) makes glucose and transports it out of the cell into the blood using GLUT2 transporters.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Regarding adipose tissue, resting skeletal muscle and liver cells (hepatocytes), which use GLUT4 transporters and which use GLUT2?

A

Adipose tissue and RESTING skeletal muscle use GLUT4 transporters for insulin intake and liver cells (hepatocytes) use GLUT2 transporters for both glucose uptake and to move glucose out of the cell in FASTED state.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the Mechanism of Action of Insulin via?

A

It is via a Tyrosine Kinase Receptor (TKR) located in the cell membrane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How does glucose affect insulin release?

A

Increased ATP production closes K+ and opens C++ channels. The opening of C++ channels releases Insulin from the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are the plasma glucose concentrations in the body during the FASTED state?

A

Around 90 mg/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the function of GLUCAGON?

A

To prevent hypoglycaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What type of receptor does Glucagon use to initiate its activity?

A

GPCR’s

46
Q

What is the primary stimulus for Glucagon release?

A

A low plasma glucose concentration.

47
Q

What is the result of dysfunction of glucose homeostasis?

A

DIABETES

48
Q

Define and explain Diabetes Mellitus

A

It is when the blood glucose concentration is chronically raised. This is called Hyperglycaemia.

  • It is due to a lack of Insulin
  • And/or a resistance to the actions of Insulin
49
Q

The overall life expectancy of Diabetes Mellitus is?

A

Reduced by 25%

50
Q

What are the common acute signs of Diabetes Mellitus?

A
  • increase urine output
  • increased thirst
  • increased hunger
51
Q

What types of complications can occur with Diabetes Mellitus?

A
  • eye disease
  • neuronal
  • kidney
  • cardiovascular
52
Q

How many types of Diabetes Mellitus are there?

A

Two.

  • Type 1 Diabetes Mellitus
  • Type 2 Diabetes Mellitus
53
Q

What is the third type of Diabetes?

A

Gestational Diabetes

54
Q

What can cause Type 1 Diabetes?

A
  • caused by loss of pancreatic beta cells
  • destruction of beta cells caused by an auto-immune response. The mechanism for this is unknown (genetic or environmental)
55
Q

Basically, what causes Type 1 Diabetes?

A

No Insulin produced

56
Q

Is Type 1 Diabetes more common in children or adults?

A

Most common in children. 95% of patients in Australia are children. The peak ages are 10-14 years of age.

57
Q

What are the symptoms of Type 1 Diabetes?

A

Thirsty: due to dehydration.

High urine output: osmotic effects of high glucose excreted in urine.

Weight loss: dehydration, loss of fluid. Use of fat and protein (muscle) as energy source.

Hungry: Body thinks it is in a FASTED state due to the inability of cells to take up glucose.

Blurry vision: Osmotic action of high glucose leads to increased water in eye and changes shape of lens
Ketoacidosis:

58
Q

What causes Type 2 Diabetes?

A

njkhiuho

59
Q

Does Type 2 Diabetes have a slow or fast onset?

A

Slow

60
Q

At approx what age does Type 2 Diabetes present?

A

Peak age is 60 years

61
Q

Type 2 Diabetes accounts for what percentage of all Diabetics?

A

85-90%

62
Q

What do over 80% of Type 2 diabetics have in common?

A

Obesity

63
Q

What are the 2 causes of Type 2 Diabetes?

A

Genetics and Environment

64
Q

In Type 2 Diabetes, what environmental factors contribute to the disease?

A

Excess consumption of food

Lack of excersice

65
Q

Does Type 1 Diabetes have a slow or fast onset?

A

Fast, sudden onset.

66
Q

Give examples of common symptoms of both Type 1 and 2 Diabetes

A

Hyperglycaemia
Excessive urine output
Thirst

67
Q

Name the 4 tests used to test for Diabetes

A
  1. Random blood glucose test
  2. Fasting blood glucose test
  3. HbA1c Test
  4. The oral glucose tolerance test (OGTT)
68
Q

When conducting an OGTT test, what glucose rise are we looking for in a normal patient?

A

Between 100 - 125 mg/dL of plasma glucose

69
Q

When conducting an OGTT test, what glucose rise are we looking for in a diabetic patient?

A

Around 225 mg/dL

70
Q

When conducting an OGTT test, what is it important to note in the patient before they consume the 75 g of anhydrous glucose dissolved in water?

A

It is important to note their plasma glucose levels before the drink is consumed. For a diabetic, we would see plasma glucose levels of around 175 mg/dL and after the drink they would rise to about 225 mg/dL

71
Q

Does Insulin reduce or increase plasma glucose?

A

Reduces

72
Q

How does Insulin reduce circulating glucose levels?

A

By allowing Glucose entry into cells

73
Q

Why do Insulin levels increase after you eat?

A

After you eat plasma glucose levels go up and this increases Insulin levels because plasma glucose stimulates Beta cells in the Pancreas. Plasma amino acids also stimulate Beta cells. When Beta cells are stimulated, Insulin is Increased.

74
Q

What pushes up Glucose levels, Insulin or Glucagon?

A

Glucagon.

75
Q

In what situation does Glucagon continue to rise and why?

A

It rises when Glucose levels continue to fall to prevent hypoglycaemia.

76
Q

Explain what factors influence Insulin release.

A

We eat food, plasma glucose goes up, plasma glucose stimulates pancreatic beta cells (so do plasma amino acids) to produce Insulin.

77
Q

Explain the anticipatory component of Insulin release.

A

We eat, feel full, bloated, guts are distended, the stretch receptors in out GIT send a signal to out brain saying we have eaten something, beta cells stimulated, Insulin activated. THE ANTICIPATORY COMPONENT IS TRANSMITTED NEURALLY.

78
Q

What happens in the anticipatory component regarding Glucose and Insulin?

A

We eat, but just prior to peak blood glucose levels Insulin is released.

79
Q

What are the 3 things that regulate Insulin release?

A
  1. A neural component, the anticipatory mechanism
  2. A hormonal component, beta cells are stimulated
  3. Glucose nutrient input, eat food
80
Q

When you eat and Glucose levels go up, what happens to Insulin levels?

A

Insulin levels go up also

81
Q

When plasma glucose goes up, are beta cells stimulated or inhibited?

A

Stimulated

82
Q

When plasma glucose goes up, are alpha cells stimulated or inhibited?

A

Alpha cells are inhibited

83
Q

Why does Glucagon try to push up levels of Glucose when you haven’t eaten?

A

To prevent Hypoglycaemia

84
Q

When plasma glucose goes down, what happens to Glucagon levels?

A

They go up to make more glucose to prevent Hypoglycaemia.

85
Q

What 4 things is Insulin important for?

A
  1. Glucose oxidation, to use glucose in the cell
  2. Glycogen synthesis, builds glycogen for later use
  3. Fat synthesis
  4. Protein synthesis
86
Q

What 3 things is Glucagon important for?

A
  1. Glycogenolysis
  2. Gluconeogenesis, new production of glucose
  3. Ketogenesis, production of Keton bodies, energy
87
Q

In the FASTED state, is Insulin or Glucagon dominant and why?

A

Glucagon is dominant because its role is to increase glucose levels when they are low to avoid Hypoglycaemia.

88
Q

How does Glucagon increase glucose levels?

A
  1. Glycogenolysis
  2. Gluconeogenesis, new production of glucose
  3. Ketogenesis, production of Keton bodies, energy
89
Q

Before it becomes a hormone, what is Insulin produced as?

A

A prohormone

90
Q

Is the Pancreas an Endocrine or Exocrine organ?

A

It is both

91
Q

What percentage of the Pancreas is Endocrine?

A

2%

92
Q

What percentage of the Pancreas is Exocrine?

A

98%

93
Q

What does an exocrine gland do?

A

It releases its products/hormones into/via ducts into its target cells.

94
Q

Name the 4 hormones the Endocrine part of the Pancreas creates.

A

Insulin
Glucagon
Amylin
Somatostatin

95
Q

Name the Islet of Langerhan cells

A

Alpha cells - Glucagon
Beta cells - Insulin, Amylin
D cells - Somatostatin

96
Q

In simple words, how does Glucose enter Adipose cells and Resting Skeletal muscles?

A

When Glucose is high after a meal, Insulin levels also increase.
The Insulin travels to the target cells and attaches itself on an RTK receptor on the cell membrane.
This activates proteins.
This moves vehicles that contain GLUT4 receptors to the cell membrane.
The vesicle fuses to the cell membrane and adds GLUT4 to it.
Glucose uses the GLUT4 receptors as a mechanism to flow down its concentration gradient and enter the cell (less Glucose in cell so it wants to move in there)

97
Q

In the FASTED state, where is GLUT4 located within the cell of Adipose cells and resting skeletal muscles?

A

GLUT4 is located within the cell in vesicles.

98
Q

Why is GLUT4 important?

A

It is the mechanism that Glucose uses to glow down its concentration gradient into the cell when its levels are high in the plasma.

99
Q

What does GLUT4 help do?

A

It helps Glucose enter the cell by being a transporter.

100
Q

Is Insulin required in WORKING skeletal muscle for the GLUT4 transporters to insert themselves onto the cell membrane?

A

No. GLUT4 expression is increased when muscles constrict which inserts the transporters to the working muscle membrane cell independently of Insulin.

101
Q

What is the name of the transporter of Glucose into Liver cells?

A

GLUT2

102
Q

Where is GLUT2 located within the Liver cells?

A

GLUT2 always sits on the surface of Liver cells.

103
Q

Summary, what are the effects of Insulin in the body and what happens when these are carried out?

A
  1. Increases utilisation of Glucose
  2. Increases Glycogen production (storage of Glucose)
  3. Increases synthesis of Proteins
  4. Increases synthesis of Lipogenesis (fat production)

All of the above REDUCE plasma glucose levels

104
Q

In simple words, how does Glucose enter Liver cells?

A

The Insulin attaches itself to GLUT2 receptors.
This increases the enzymes involved in in the utilisation of Glucose so that the concentration of free Glucose in the cells is maintained low.
So Glucose moves down its concentration gradient.
It uses GLUT2 receptors to do that.

105
Q

What does Glycolysis mean?

A

The breakdown of Glucose by enzymes.

106
Q

What does Glycogenesis mean?

A

The making of Glycogen from sugar.

107
Q

What does Glycogenolysis mean?

A

The breakdown of Glycogen.

108
Q

What does Lipolysis mean?

A

The breakdown of fat.

109
Q

What receptor does Insulin use on cell membranes?

A

TRK receptors

110
Q

What happens when Insulin attaches to its TRK receptor on the cell surface?

A

When the RTK receptor is activated by Insulin,
It allows IRS (insulin receptor substrate) to be activated.
How is it activated? By attaching a phosphate group to it.
This allows the IRS to produce 2nd messengers.
The 2nd messengers influence expression of genes.
The 2nd messengers also translocate the GLUT4 receptors to the cell surface.

Endocrinology (5 decks)

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