Lecture 29 Flashcards
(11 cards)
1
Q
What is the typical range for glucose levels?
A
3.5-6 (fasting), 3.5-8 nonfasting
2
Q
What are acini?
A
Pancreatic cells, secrete enzymes into ducts which empty into intestine (exocrine glands)
3
Q
What are pancreatic islets?
A
clusters of endocrine cells scattered throughout acini
4
Q
What do alpha cells do?
A
secrete glucagon, increase bgl
5
Q
What do beta cells do?
A
secrete insulin, decrease bgl
6
Q
how is insulin made
A
- Protein hormone Initially synthesized on RER of beta cells as preprohormone with A, B and C chains
- C chain removed in golgi
- Insulin (and C peptide) released from beta cells when BGLs rise
- Circulates unbound in plasma and mostly cleared from circulation within 10-15 minutes
7
Q
how do insulin receptors work?
A
- Insulin binds to alpha subunits
- beta subunits then get
phosphate groups attached
from ATP - Beta subunits then able to
phosphorylate proteins inside
the cell that mediate insulins
effects - Insertion of GLUT4 transporters into cell membrane of muscle and fat cells
- Activation/inactivation of
specific enzymes pathways in
various cells - effect depends on cell
8
Q
what is lipolysis?
A
fat breakdown, insulin inhibits
9
Q
what are the effects of insulin on the liver
A
- store as glycogen
- fatty acid synthesis, if too much glucose is stored in very low density lipoprotein as triglyceride
- inhibit glycogenolysis (breakdown of glycogen)
- inhibit gluconeogenisis
- Suppresses the formation of ketone bodies
10
Q
What is glucagon?
A
- Polypeptide hormone secreted by alpha cells of pancreatic islets primarily in response to HYPOGLYCEMIA
- Glucagon exerts its effects (primarily on the liver) via
activation of receptors that utilize cAMP as second
messenger.
11
Q
difference between type 1 + 2 diabetes
A
type 1 = autoimmune
type 2 = body gives up on u and ur poor habits
