The Endocrine Pancreas 2 Flashcards
1
Q
What is the primary purpose of glucagon?
A
- To raise blood glucose
2
Q
Glucagon has a half life of __ minutes and degrades mainly in the _______
A
- 5-10 minutes
- Liver
3
Q
Glucagon is most active in the absorptive/ post-absorptive state
A
- Post-absorptive
4
Q
Describe the mechanism by which glucagon performs its main function
A
- Glucagon binds to its receptors on the hepatic cell membrane: G-protein coupled receptors
- These G-protein coupled receptors are linked to the adenylate cyclase/ cAMP system
- The adenylate cyclase/ cAMP system becomes activated and causes the phosphorylation of liver enzymes
- This results in: Increased glycogenolysis, increased gluconeogenesis and the formation of ketones from fatty acids (lipolysis)
5
Q
Amino acids in the plasma stimulates the release of
A
- Both insulin AND glucagon
(this allows for the maintainance of blood glucose following ingestion of a high protein low carb meal)
6
Q
State the stimuli that promote glucagon release
A
- Low blood glucose
- High amino acids in the blood
- Sympathetic innervation and epinephrine, β2 effects
- Cortisol
- Stress e.g exercise, infection
7
Q
State the stimuli that inhibit glucagon release
A
- Glucose
- Free fatty acids and ketones
- Insulin
- Somatostatin
8
Q
Discuss the ANS innervation of islet cells
A
9
Q
What is the main pancreatic action of somatostain?
A
- Inhibits activity in the GI tract
10
Q
What does somatostatin do to insulin and glucagon?
A
- Somatostatin strongly suppresses/ inhibits the release of both insulin and glucagon in a paracrine fashion
