Blood glucose — negative feedback

Variable: blood glucose · set point 5.0 mmol/L · normal range 4.0–6.0 mmol/L. Feedback corrects a deviation; it does not hold the value still.

Glucose · insulin · glucagon

Clock 0:00 running

Insulin 15%

Secreted by beta (β) cells of the islets of Langerhans, pancreas.

Target effect: glucose uptake into muscle and adipose tissue, and glycogenesis in the liver — lowers glucose.

Glucagon 15%

Secreted by alpha (α) cells of the islets of Langerhans, pancreas.

Target effect: glycogenolysis and gluconeogenesis in the liver — raises glucose.

Run the model

Set glucose (mmol/L)12.0

Jumps glucose to that value now, then lets the loop respond.

Meal (mmol/L)+6.0

Exercise (mmol/L)−4.0

Set point (mmol/L)5.0

Response delay10 min

Longer delay → bigger overshoot past the set point.

Impairment

Glucose now

5.00

mmol/L · in range

Deviation

0.00

from set point

Dominant hormone

Balanced

both at baseline

Overshoot last run

—

lowest point after a rise

Interpretation

At the set point