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Flashcards in 20. Acute Regulation of Glucose Deck (21):
1

How are B-cells stimulated to release insulin?

1. Detection - blood glucose is picked up by B-cells via GLUT-2 transporters and used to make ATP
2. Depolarisation - ATP production blocks K+ pump in the cell causing the membrane to depolarise
3. Release - Calcium influx causes exocytosis of insulin.

2

There is a greater spike in insulin levels after taking IV glucose rather than orally.
True or False?

FALSE
insulin levels are much higher after taking glucose orally.

3

Why is there a difference between insulin levels when glucose is taken orally vs. IV?

ACh & CCK signals from the GI tract also stimulate insulin release from B-cells.
IV glucose does not induce these signals, so there is less overall insulin release.

4

Is insulin secretion driven by the sympathetic or parasympathetic nervous system?

Parasympathetic nervous system

5

How marker can you use to measure endogenous insulin production? (how much insulin someone makes themselves)

C peptide (cleaved off of proinsulin to form insulin)

6

What is the receptor for insulin?

Tyrosine kinase receptor

7

Liver cells contain GLUT-4 transporters.
True or False?

FALSE
only GLUT-2

8

What effects does insulin have on the liver?

1. ↑ glycogenesis
2. ↑ VLDL production
3. gluconeogenesis inhibited
4. Ketone body production inhibited

9

What effects does insulin have on muscle?

1. GLUT-4 inserted to increase glucose uptake
2. ↑ glycogenesis
3. ↑ lipogenesis
4. ↑ protein synthesis

10

What effect does insulin have on fat (adipocytes)?

1. GLUT-4 inserted to increase glucose uptake
2. ↑ lipogenesis
3. ↓ export of fatty acids + glycerol into blood

11

What effect does glucagon have on the liver?

1. ↑ glycogenolysis
2. ↑ gluconeogenesis

12

Glucagon is a GPCR.
True or False?

TRUE

13

What effect does glucagon have on fat and muscle?

Fat = lipolysis
Muscle = proteolysis

14

Somatostatin inhibits:
CCK, secretin, gastrin, insulin, glucagon.
True or False?

TRUE

15

Exercise releases adrenaline, what effect does this have on metabolism?

1. ↑ glucose production in liver
2. glycogen breakdown in muscle
3. GLUT-4 insertion
4. Fatty acid release from adipocytes

16

What does a high urine volume and the presence of glucose indicate?

Diabetes mellitus.
Lack of insulin action cause high plasma glucose levels which is lost in urine, water follows by osmosis.

17

Why do people with type 1 diabetes lose weight?

Cannot produce enough insulin due to B-cell destruction by immune system.
Therefore there is more glucagon present that insulin.
Leading to:
lipolysis, proteolysis, gluconeogenesis, ketogenesis.

18

What is the issue in type 2 diabetes?

Insulin resistance

19

What is the difference between type 1 & 2 diabetes management?

Type 1: always need insulin.
Type 2: Diets to reverse problem, drugs to enhance insulin secretion and sensitivity.

20

Where is insulin produced?

β-cells in the Islets of Langerhans in pancreas

21

Where is glucagon produced?

α-cells in the Islets of Langerhans in pancreas