The Endocrine Pancreas

Question 1

What do each type of cell within the endocrine pancreas produce?

Answer 1

Beta cells- Insulin
Alpha cells- Glucagon
Delta cells- Somatosatin

Question 2

What is the normal blood glucose range in millimoles?

Answer 2

4.2-6.3mM

Question 3

In milograms per decilitre what is the normal BG range?

Answer 3

80-120mg/dl

Question 4

What value of blood glucose would be considered hypoglycaemia?

Answer 4

<3mM

Question 5

What is the name given to the endocrine portions of the pancreas?

Answer 5

Islets of Langerhans

Question 6

What are the functions of insulin?

Answer 6

Allows uptake of glucose in insulin dependant tissues.
Increases uptake of glucose in liver
Inhibits gluconeogenesis (the synthesis of glucose), lipolysis and proteolysis.
Stimulates lipogenesis and protein synthesis
Promotes K+ uptake in to cells
Permissive effect on Growth hormone
Increases amino acid uptake

Overall it decreases blood glucose levels.

Question 7

What stimulates insulin release?

Answer 7

Increased BG
Increased amino acid blood levels
Glucagon (as when glucose created the insulin is required so it can be taken up where it is needed)
Incretin hormones controlling GI secretion, and motility (e.g. gastrin, secretin)
Vagal nerve activity

Question 8

What are the functions of glucagon?

Answer 8

Increased glycogenolysis (glycogen breakdown)
Increased gluconeogenesis (glucose synthesis from aa's and glycerol)
Ketone formation from fatty acids (lipolysis)

Stimulated by:
low BG
high aa's
sympathetic stimulation of Islets of Langerhans
cortisol (stress hormone)
stress e.g. exercise, infection

Question 9

What does somatostatin do?

Answer 9

Also called Growth hormone inhibiting hormone, this inhibits both insulin and glucagon secretion.
This means the absorption of nutrients is slowed down.
The net affect is an increase in BG
Somatostatin/GHIH is also produced at the hypothalamus