Control of blood glucose concentration

Homeostasis and response · Hormonal coordination in humans · note 2 of 11

Spec 4.5.3.2Download these notes (PDF)12 pages

Control of blood glucose concentrationSpec 4.5.3.2

Blood glucose concentration is monitored and controlled by the pancreas.

If the blood glucose concentration is too high, the pancreas produces the hormone insulin. Insulin causes glucose to move from the blood into the cells. In liver and muscle cells excess glucose is converted to glycogen for storage.

Blood glucose concentration rises (for example after a meal).
The pancreas detects this and produces insulin.
Insulin causes glucose to move from the blood into the cells.
In the liver and muscle cells, excess glucose is converted to glycogen.
Blood glucose concentration falls back to the normal level.

Higher tier

Glucagon and negative feedback

Higher tier

If the blood glucose concentration is too low, the pancreas produces the hormone glucagon. Glucagon causes glycogen to be converted into glucose and released into the blood.

Higher tier

Insulin and glucagon work against each other in a negative feedback cycle. When one hormone brings the glucose level back to normal, the pancreas stops releasing it. This keeps blood glucose near the normal level.

Higher tier

Insulin and glucagon
	Insulin	Glucagon
Released when blood glucose is	Too high	Too low
Effect on glucose	Glucose moves from blood into cells	Glycogen is converted into glucose and released into the blood
Effect on blood glucose	Falls	Rises

Negative feedback loop for blood glucose: when glucose is too high the pancreas releases insulin and glucose moves into cells, so glucose falls back to normal; when glucose is too low the pancreas releases glucagon and glycogen is converted into glucose, so glucose rises back to normal. — Insulin and glucagon keep blood glucose near normal by negative feedback.