Endocrine Pancreas 2

Question 1

What is glucagon?

Answer 1

Peptide hormone produced by alpha cells of the pancreatic islet cells

Question 2

What is the primary purpose of glucagon?

Answer 2

to RAISE blood glucose

Question 3

What is it described as in terms of its action?

Answer 3

a glucose-mobilizing hormone

Question 4

Where does glucagon act in the body?

Answer 4

Mainly on the liver

Question 5

What is glucagon’s plasma half-life?

Answer 5

5-10 mins (degraded mainly by liver)

Question 6

Glucagon primarily opposes the action of insulin, and forms part of what system?

Answer 6

Glucose counter-regulatory control

Question 7

What hormones are involved in the glucose counter-regulatory control system?

Answer 7

Glucagon
Epinephrine
Cortisol
GH

Question 8

In what bodily state is glucagon most dominant?

Answer 8

Post-absorptive

Question 9

Describe glucagon receptors

Answer 9

G-protein coupled receptors linked to the adenylate cyclase/cAMP system

Question 10

When the adenylate cyclase/cAMP system is activated by glucagon receptors, what happens?

Answer 10

Phosphorylates specific liver enzymes

Question 11

What does phosphorylation of specific liver enzymes from the adenylate cyclase/cAMP system result in (3 hings)?

Answer 11

1. Increased glycogenolysis
2. Increased glucneogenesis
3. Formation of ketones from fatty acids (lipolysis)

Question 12

What are the substrates for increased gluconeogenesis?

Answer 12

AA’s and glycoerol (lipolysis)