Wk2 Pancreas Phys Flashcards
Alpha cells secrete:
glucagon
Somatostatin comes from what cell?
D cells
Ketone bodies are a product of…
fat metabolism
Time in fasted state when glycogen in muscle and liver runs out:
within 24 hours
Enzyme unique to liver that allows glucose from glycogen to be released into blood:
G-6-P
Insulin effect on fat tissue:
inhibits lipolysis
promotes accumulation of TGs
Myocyte stimulators that trigger glycogenolysis:
Epi – B2 receptors
4 main roles of insulin in fed state:
- glucose oxidation
- glycogen synthesis
- fat synthesis
- protein sysnthesis
3 main roles of glucagon in fasted state:
- glycogenolysis
- gluconeogenesis
- ketogenesis
Sympathetic effect on insulin in pancreatic Beta cells:
inhibits release
**fight or flight –> need sugar in blood
Parasympathetic effect on insulin in beta cells:
cephalic phase of insulin secretion via vagus
**main regulator of beta cell insulin release:
GLUCOSE
How does glucose get into beta cells:
GLUT2
Once in the cell, how does glucose stimulate insulin release from beta cells:
glycolysis –> ATP
ATP –> CLOSES K+ channel –> DEpolarizes cell
–> increases Ca++ via voltage gated Ca channels
–> Ca++ causes release of insulin from vesicles fusing with membrane
Effect of thiazide diuretics on beta cells:
OPEN K+ channels –> hyperpolarization –> no insulin release –> hyperglycemia
Look at and understand Glucagon and GLP-1 in slide…
17
Insulin receptor type in peripheral tissues:
tyrosine kinase –> growth factor
Glucagon response to amino acids:
Why?
Increases
to protect from hypoglycemia in all protein meal
Glucagon receptor type:
Gs –> AC –> cAMP –> PKA –> PPK –> PYG
Somatostatin effect on pancreatic hormones:
inhibits everything
insulin effect on somatostatin release:
stimulates
Grehlin effect on somatostatin release:
inhibits
What are incretins?
GI hormones that mediate intestinal phase of insulin secretion
GLP-1 – L cells of lower small intenstine
GIP – K cells of duodenum and jejunum
4 phases of insulin secretion:
- cephalic – PNS – sight smell
- oral – taste
- GI – GIP and GLP-1
- Blood glucose phase – direct stimulation of Beta cells