Homeostasis IGCSE Biology: Temperature & Glucose

Homeostasis: Temperature and Blood Glucose Control

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

Key concept

Homeostasis maintains a constant internal environment. Negative feedback detects a deviation and activates responses that reverse it, including sweating or shivering for temperature and insulin or glucagon for blood glucose.

Homeostasis answers score when written as a chain: change, detection, coordination, effector response and return toward the normal level. Lists of body responses without the direction of change usually lose the explanation marks.

The negative-feedback structure

A receptor detects a change from the normal level. A coordination centre processes the information and sends signals to effectors. The response opposes the original change, bringing the condition back toward normal.

Negative does not mean harmful. It means the response reverses the deviation.

When body temperature rises

Sweat glands release more sweat; evaporation transfers thermal energy from the skin. Skin arterioles dilate, increasing blood flow through capillaries near the surface, so more energy is lost to the surroundings. Hairs lie flatter and metabolic heat production can decrease.

When body temperature falls

Skeletal muscles shiver, increasing respiration and heat release. Skin arterioles constrict, reducing blood flow near the surface. Hairs may rise to trap an insulating air layer, and metabolic heat production increases.

Vasoconstriction does not mean capillaries themselves actively become narrow; arterioles supplying them constrict.

Insulin and glucagon

When blood glucose rises, the pancreas releases insulin. Cells take up more glucose, and the liver and muscles convert glucose to glycogen, lowering the concentration. When blood glucose falls, glucagon promotes conversion of glycogen to glucose in the liver, raising it.

Type 1 diabetes involves insufficient insulin production and can be managed with insulin, diet and monitoring.

Try a focused question (4 marks)

After a carbohydrate-rich meal, blood glucose concentration rises. Explain how it returns toward normal.

Show the answer and marking guidance

The pancreas detects the rise and releases insulin.
Insulin causes body cells to take up more glucose.
The liver or muscles convert glucose to glycogen.
Blood glucose concentration falls toward the normal level by negative feedback.

Original Cambridge-style practice written for this site. It is not an official Cambridge past-paper question.

Common mix-ups to avoid

Check these points against your own answer before moving on.

Saying insulin converts glucose directly rather than stimulating cells or organs to do so.
Writing that glucagon lowers blood glucose.
Describing sweating without evaporation.
Naming responses without explaining how they reverse the change.