Diabetes PB

Question 1

Where is insulin produced and secreted from?

Answer 1

Pancreas

Question 2

What are the 4 different islet of Langerhans cells?

Answer 2

A (alpha) cells
B (beta) cells
D (delta) cells
F cells which secrete pancreatic polypeptides

Question 3

What do alpha cells secrete?

Answer 3

Glucagon which increases blood glucose

Question 4

What do beta cells secrete?

Answer 4

Insulin which decreases blood glucose levels

Question 5

What do delta cells produce?

Answer 5

Gastrin &
somatostatin (this inhibits secretion of glucagon and insulin)

Question 6

Describe how hyper and hypoglycaemia stimulate A and B cells

Answer 6

Hyperglycaemia stimulates B cells to secrete insulin to reduce blood glucose levels
Hypoglycaemia stimulates A cells to secrete glucagon which acts on hepatocytes to convert glycogen to glucose

Question 7

What do GLUT-1 & 2 etc do?

Answer 7

Transport glucose across cell membrane at a faster rate than diffusion

Question 8

How do GLUT-4 receptors act?

Answer 8

-Bind to insulin receptor on the surface of the cell membrane (alpha side)
-This generates an intracellular signal
-Which causes insertion of GLUT-4 from its inactive site into the cell membrane
Hence the transport of glucose across the cell membrane

Question 9

What is GLUT-4?

Answer 9

Insulin dependant glucose transporter for skeletal muscle and adipose tissue. It is inactive and inside the cell membrane. It becomes active when insulin causes it to move from its inactive sire to cell membrane

Question 10

Why is GLUT-2 important?
(in red)

Answer 10

Major glucose transporter into B-cells and liver cells. It has low affinity for glucose and acts when glucose plasma levels are high

Question 11

Why is GLUT-1 important?

Answer 11

In all tissues & does not require actions of insulin. Important for transport of glucose into cells of the nervous system

Question 12

Briefly explain T1 diabetes

Answer 12

B cell destruction = absolute insulin deficiency (70% of diabetes) No B cells—> no insulin released
Autoimmune T-cell mediated (type 1A)
Idiopathic (type 1B)

Question 13

Briefly explain T2 diabetes

Answer 13

Insulin resistance
Adult onset typically, inadequate response to insulin
Age related >50 higher risk as organs start declining

Question 14

Can diuretics cause diabetes?

Answer 14

Yes- high dose thiazide

Question 15

What is gestational diabetes?

Answer 15

Diabetes which occurs in pregnancy (only 6%) caused by excess hormone production which causes insulin resistance

Question 16

What are the risks involved with gestational diabetes?

Answer 16

At higher risk if obese or prior family history/ had it in previous pregnancies

Neonatal hyperglycaemia, Respiratory distress syndrome, macrosomia and microsomia

Question 17

How do you treat gestational diabetes?

Answer 17

Once child is delivered the diabetic effect goes away so no treatment necessary

Question 18

When is T1 diabetes seen? at what age?

Answer 18

Develops in childhood, shows in puberty and progresses with age

Question 19

What are the 3 polys of diabetes? MCQ

Answer 19

Polyuria (excessive urination)
Polydipsia (excessive thirst)
Polyphagia (excessive hunger)