Lecture 6

Question 1

BGL regulation

Answer 1

Fasting BGLs are between 3.9-5.4mMol/L. Normal BGLs two hours after starting a meal are between 6-10mMol/L.

Question 2

Hypoglycaemia

Answer 2

BGLs < 4mmol/L

Question 3

Hyperglycaemia

Answer 3

BGLs > 7mmol/L

Question 4

Factors that increase BGLs for fasting

Answer 4

absorption from intesine
glycogen -> glucose
synthesis of glucose from non-carb sources
hyperglycaemic hormones like glucagon

Question 5

Factors that decrease BGLs for fasting

Answer 5

utilisation by tissues
glycogen synthesis
storage of glucose as fat
insulin

Question 6

B cells

Answer 6

produce insulin (peptide hormone)

1. GLUT2 mediated transport of glucose into the B cells where glucose if phosphorylated into G6P by glucokinase
2. G6P moves through the glycolysis pathway to form pyruvate which enters Krebs cycle
3. In the mitochondria, O2 respiration generates ATP, the increase for ATP/ADP ratio. ATP binds and closes ATP-sensitive K+ channels.
4. Depolarisation of plasma membrane opens Ca2+ channels
5. Influx of Ca triggers insulin granule exocytosis

Question 7

Incretins

Answer 7

Hormone secreted by the gut in response to a meal. They generate glucose induced insulin secretion in B cells. Increase [insulin]blood. Glucose given orally stimulates more insulin than intravenous/intraperitoneal glucose as it goes to the gut therefore, therefore incretin effect can take place.