Insulin production, secretion and action

Question 1

What is diabetes?

Answer 1

Loss of Glucose Homeostasis leading to hyperglycaemia

Question 2

What does the statement “ the release of insulin is biphasic” mean?

Answer 2

It comes in two waves

Question 3

What is happening top right?

Answer 3

Increased ATP inhhibits ATP-sensitive potassium channels

Blocks potassium exiting the cell

Cell depolerisation

Question 4

What cells are found within the islets of Langerhans?

Answer 4

Alpha cells

Beta Cells

Delta cells

PP cells

Question 5

What enzyme is responsible for the phsophorylisation of Glucose?

Answer 5

Glucokinase

Question 6

What do alpha pancreatic cells secrete?

Answer 6

Glucagon

Question 7

What are the risk factors for Type 2 diabetes

Answer 7

Fat poncho

Family history

Age

Asian or African

Phx of stroke/MI

antipsychotics

Question 8

What does mellitus mean?

Answer 8

Honey

Sweet

Question 9

Which cells secrete glucagon?

Answer 9

Pancreatic Alpha cells

Question 10

What is Diabetes Mellitus?

Answer 10

Group of metabolic disease characterized by hyperglycemia resulting from defects in insulin secretions, insulin action or both

Question 11

What is this?

Answer 11

Islet of Langerhans

Question 12

What is Type 4 diabetes?

Answer 12

Any degree of glucose intolerance arising or diagnosed around pregnancy

Question 13

What is an insulin receptor?

Answer 13

Dimeric tyrosine kinase

Question 14

What does diabetes mean?

Answer 14

Insufficient insulin to maintain glucose homeostasis

Question 15

What is happening bottom right?

Answer 15

Increase in calcium ion concentration leads to the fusion of secretory vescles and the release of insulin

Question 16

What is the Disease mechanisim for type 1 diabetes?

Answer 16

Auto immune disorder leading to destruction of insuling producing cells ( Beta cells within the islet of langerhans)

Question 17

What is the normal blood glucose ?

Answer 17

4-6 millimoles per litre

4 is the floor

Question 18

Which cells secret insullin?

Answer 18

Pancreatic beta cells

Question 19

How does Diabetes Mellius present?

Answer 19

Thirst

Polyuria

Thrush

Fatigue

Blurred vision

infections

Question 20

What is happening bottom right?

Answer 20

Depolarisation of the cell membrane results in opening of

voltage-gated caclium ion channels

Question 21

How do insluin receptors work?

Answer 21

binding of insulin to the extracellular alpha subunits causes the transmembrane beta subunits to phsophorylate

Question 22

What does each cell within the islet of langerhans secrete?

Alpha cells

Beta cells

Gamma cells

PP calls

Answer 22

Alpha = Glucagon

Beta = Insulin

Gamma = Somatostatin

PP cells = Pancreatic polypeptide

Question 23

Which organ produces Insulin and Glucagon?

Answer 23

Pancrease

Question 24

What is the precursor to insulin which is then cleaved to form insulin?

Answer 24

preproinsulin

Question 25

Would you find ketoacidosis in type 1 or type 2 diabetes?

Answer 25

Type 1

Question 26

Which tests can be used to diagnose Diabetes?

Answer 26

Random glucose Fasting glucose 2-hr glucose in OGTT HbA1c

Question 27

What is hbA1c?

Answer 27

Glycated haemoglobin gives an idea of glucose control over the last 3 months

Question 28

What is the by product of preproinsulin clevage and why is it useful?

Answer 28

Connecting (C) peptide Can be measure to monitor insulin production

Question 29

What do pancreatic beta cells secrete?

Answer 29

Insulin

Question 30

What is type 3 diabetes?

Answer 30

Diabetes secondry to pancreatic or endocrine disease or medication

Question 31

Which part of pancreatic beta cells produce the insulin?

Answer 31

Question 32

What is happening top left?

Answer 32

Glucose enters the beta cell through GLUT2 glucose transporter Get phosphorylated by Glucokinase. Produces ATP

Question 33

What does the sulphonylurea class of drugs do?

Answer 33

Stops the potassium ATP pump Increasing insulin production

Question 34

What does diazoxide do?

Answer 34

Stimulates the potassium ATP pump inhibitting insulin secretion