Negative feedback
A control system where a change triggers a response that reverses the change and brings the body back to normal.
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Analogy
Like cruise control easing off the accelerator when the car goes too fast.
In practice
High blood glucose causes insulin release, which lowers glucose again.
Practice
Flashcards
- Which gland controls blood glucose with insulin?The pancreas.
Interview questions
- Describe how blood glucose is kept steady after a meal.
- Glucose rises after eating
- The pancreas releases insulin
- Insulin makes the liver store glucose as glycogen
- Blood glucose falls back to normal, which is negative feedback
Questions people ask
Why is it called negative feedback?
The response goes in the opposite direction to the change. If glucose goes up, the response brings it down. If it goes down, the response brings it up. Negative here does not mean bad. It means the system works against the change to return to its normal level.
What is an example of negative feedback in temperature control?
If blood temperature rises above normal, the brain triggers sweating and wider skin vessels, which cool the body. Once the temperature returns to normal, those responses switch off. If it drops, the brain triggers shivering and narrowed vessels to warm you. The system keeps swinging back to the middle.