Glucose Homeostasis Flashcards
What is the normal level of blood glucose?
About 80-110/100 ml
Alpha cells from pancreas respond to____
Hypoglycemia
What hormone is released by alpha cells of the pancreas?
Glucagon
Glucagon targets…
Liver and adipose
Glucagon in the liver increases which pathways?
Glycogenolysis, gluconeogenesis, beta oxidation of fats (termed ketogenesis)
Glucagon in adipose increases which pathway?
Lipolysis
What does the hypothalamus respond to?
Hypoglycemia plus exercise or sleep
What hormone does the hypothalamus release?
Growth hormone
growth hormone targets which organs?
Liver and muscle (which responds to somatomedin C and GH)
What happens to growth hormone in the liver?
GH is converted to insulin like growth factor 1 AKA somatomedin C
What pathways are increased by growth hormone in muscle?
Increases amino acid uptake, protein synthesis, and beta oxidation fats
What pathways are decreased by growth hormone in muscle?
Decreases protein breakdown and carbohydrate metabolism
What does the adrenal medulla respond to?
Hypoglycemia plus acute stress
What hormone is released by the adrenal medulla?
Epinephrine
Where are the target organs of epinephrine?
The liver, adipose, and muscle
What pathways are increased by epinephrine in the liver?
Glycogenolysis, gluconeogenesis, Beta oxidation of fats termed ketogenesis
What pathways are increased by epinephrine in adipose?
Lipolysis
What pathways are increased by epinephrine in muscle?
Glycogenolysis, Kreb’s cycle, beta oxidation of fats
What does the adrenal cortex respond to?
Chronic stress and does not need hypoglycemia to be released
What hormone does the adrenal cortex release?
Cortisol
What pathways are increased by cortisol in the liver?
Glycogenolysis, gluconeogenesis, and beta oxidation of fats (ketogenesis)
What pathway is increased by cortisol in adipose?
Lipolysis
What affect does cortisol have on muscle?
Blocks the Glut 4 transporter
Hypoglycemia causes the release of which hormones?
Glucagon, growth hormone, epinephrine, and cortisol
Hyperglycemia causes the release of which hormones?
Insulin and somatostatin
What do beta cells of the pancreas respond to?
Hyperglycemia
What hormone do beta cells of the pancreas release?
Insulin
What pathways are increased by insulin in the liver?
Glycogenesis, glycolysis, triacylglycerol (TAG) synthesis, cholesterol synthesis
What affect does insulin have on adipose?
Stimulates Glut 4 transporter and glucose enters TAG storage
What affect does insulin have on muscle?
Stimulates Glut 4 transporter and glucose enters
Increased glycogenesis, glycolysis, Kreb’s, electron transport
What do delta cells from pancreas respond to?
Hyperglycemia
What hormone is released by delta cells from pancreas?
Somatostatin
What organs are targeted by insulin?
Liver, adipose, and muscle
What organs are targeted by somatostatin?
Hypothalamus and anterior pituitary
What is the effect of somatostatin on the hypothalamus and anterior pituitary?
Decreases release of GHRH and growth hormone
Name 2 cycles that raise blood glucose
Glycogenolysis
Gluconeogenesis
What five components are involved in the regulation of blood sugar?
Brain, RBC, liver, muscle, adipose tissue
Which of the components involved in regulation of blood sugar have an absolute requirement for glucose?
Brain and RBC
What glucose transporter do the brain and RBC use?
Glut-1 insulin independent
What glucose transporter does the liver use?
Glut-2 insulin independent
What glucose transporter do muscle and adipose tissue use?
Glut-4 insulin dependent
Which glucose transporter allows glucose in and out?
Glut-2 insulin independent
Which way do Glut-1 insulin independent and Glut-4 insulin dependent transporters allow glucose to go?
In only
