Connect the complete temperature regulation loop
Combine brain coordination, insulation, sweating, shivering and arteriolar flow.
Exam scope and assessment notes
Extended only (Supplement) · Biology 0970, 2026–2028. Use the stated specimen features and evidence. Diagrams are schematic. Written practice is self-checked; human subject-teacher review, supervised practical competence and cumulative assessment remain pending. Cambridge states that IGCSE 0970 has the same subject content as IGCSE 0610, with 9–1 grading. This StudyForA pathway maps the 2026–2028 syllabus only. This 9–1 graded qualification is available only in a limited number of administrative zones. Confirm that your centre can enter you for this code and exam series with Cambridge International. Cambridge has published a separate syllabus for 2029. StudyForA has not reconciled that version yet; this page supports exams in 2026, 2027 and 2028 only.
Before you begin
- Recall hormone production and blood transport, respiration, liver storage and electrical impulses along neurones.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which cold-response pairing combines production and conservation?
What you will learn
- Choose a coordinated response to each departure
- Explain feedback and separate the physical mechanisms
Connect the complete temperature regulation loop
| Feature | Meaning |
|---|---|
| Brain | Temperature information → coordination |
| Warm | Sweating; arteriole dilation; heat loss in cooler surroundings |
| Cold | Shivering; arteriole constriction; insulation |
| Closure | Return reduces stimulus and corrective response |
Choose a coordinated response to each departure
A complete thermoregulation account begins with a departure of internal temperature from its regulated level and information reaching the brain. The coordinating system changes effector activity. Responses are chosen to oppose the departure, and as temperature returns the original corrective stimulus and increased response diminish. That final return link is what closes the negative-feedback loop.
After a rise, increased sweating allows evaporation to remove heat from the skin. Vasodilation widens the arterioles supplying surface capillaries and increases surface blood flow, supporting heat loss when surroundings are cooler than the body. Hair lying flatter can reduce trapped-air insulation in furry mammals, while the substantial human cooling mechanisms are not attributed to a dense fur coat.
Explain feedback and separate the physical mechanisms
After a fall, shivering increases skeletal muscle respiration and heat production. Vasoconstriction narrows the supplying arterioles and reduces surface flow and heat loss. Hair erector contraction can raise a furry coat and trap insulating air; subcutaneous fatty tissue also provides insulation. Human hair insulation is limited, and fat does not have to generate heat to reduce transfer.
Keep the mechanisms distinct while showing how they cooperate. Brain coordination is not sweat secretion; evaporation removes heat, shivering produces heat, and insulation plus reduced skin flow conserve heat. Arterioles change lumen while capillaries stay in position. Environmental temperature and humidity affect heat transfer, so the simplified loop is a physiological teaching model rather than a personal medical plan.
Pause and explain
Which statement completes the loop?
Worked example
Explain coordinated correction after internal temperature falls.
Show the worked solution
- Brain coordinates shivering, reduced skin flow and relevant insulation.
- Production increases and loss decreases; return reduces the corrective stimulus.
Answer Brain coordination increases shivering heat production and reduces heat loss through arteriolar vasoconstriction and insulation. Return towards the regulated level reduces the corrective response.
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Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Explain the complete warm-response loop in cooler surroundings.
Give me a hint
Include brain, two effectors and loop closure.
Compare my reasoning
- Brain coordinates sweating and arteriolar vasodilation.
- Evaporation and increased surface flow remove heat; return reduces the response.
Brain coordinates increased sweating and vasodilation of arterioles supplying surface capillaries. Evaporation and increased surface flow promote heat loss to cooler surroundings; return towards the regulated level reduces the corrective stimulus and response.
Look for these in your work
- Explain both warm mechanisms
- Close the negative-feedback loop
Explain the complete cold-response loop, distinguishing production and insulation.
Give me a hint
Include shivering, vessels and insulating structures.
Compare my reasoning
- Shivering muscle respiration increases heat production.
- Vasoconstriction, subcutaneous fat and raised furry hair reduce loss.
Brain coordinates shivering heat production and heat conservation through arteriolar vasoconstriction and insulation by fat and a raised furry coat where present. Human hair insulation is limited. Return reduces the corrective response.
Look for these in your work
- Separate production from conservation
- Include coordination and feedback
Correct a model claiming fat secretes sweat, capillaries move, and all responses always lose heat even in hotter surroundings.
Give me a hint
Assign each role to the correct structure and condition.
Compare my reasoning
- Sweat glands secrete sweat; fat insulates; arterioles change lumen.
- Capillaries stay in place, and heat transfer depends on the environment.
Sweat glands secrete sweat whose evaporation removes heat; fat insulates. Supplying arterioles widen or narrow while capillaries stay in place. Heat-transfer direction depends on conditions, so outward-loss claims need cooler surroundings.
Look for these in your work
- Correct structure-function assignments
- State the thermal condition
Common mistakes
- Merging sweating, shivering and insulation into one process.
- Omitting return-to-stimulus feedback.
What can you explain now?
Which statement completes the loop?
Compare with the explanation
Return towards reference reduces corrective stimulus and response
It connects response success back to control.
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Make it stick
Explain the full coordinated loop and keep evaporation, production and conservation distinct.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.