Body Temperature Regulation

Activities to try

1. 1

   Hold the body at 37°C: a negative-feedback model

   Why it works: Thermoregulation is a self-correcting control loop, not just a list of reactions: the body senses a deviation and acts to reverse it (negative feedback), and a constant ~37°C is needed so enzymes keep working — overheating denatures them, while severe cold slows them.

   1. Change a simulated environment to blazing heat or biting cold and watch a core-temperature dial begin to drift away from 37°C.
   2. Observe and name the responses that fire: in heat, skin vessels widen (skin reddens, more blood near the surface) and sweat appears and evaporates, so the dial eases back down; in cold, vessels narrow, shivering begins, and the dial climbs back up.
   3. Follow a feedback-loop diagram that lights stage by stage — stimulus → detect (receptors in skin and brain) → control centre in the brain (hypothalamus) processes and signals → respond (effectors) → return to set point — and state in your own words how each response OPPOSES the original change.
   4. Use a 'switch off responses' control: with feedback disabled in a HOT environment, watch core temperature overshoot 37°C until an enzyme-denaturing warning appears; in a COLD environment the dial instead falls below 37°C and enzymes slow down rather than denature. Either way, explain why the loop matters.
   5. Predict before each manipulation what the body should do, then check against the model.
2. 2

   Label the skin and bust the 'wet = cool' myth

   Why it works: Names the structures and responses accurately and understands that sweat cools by evaporation (change of state removing heat), not by being wet or cold, and that vasodilation/vasoconstriction is widening/narrowing rather than vessel movement.

   1. Explore a labelled skin cross-section (sweat glands, blood vessels near the surface, hair erector muscles) and attach each structure to a cooling or warming role, noting that hair erector muscles (goosebumps) trap an insulating air layer in furry animals but have very little warming effect in humans.
   2. Explain for each: sweat evaporates and takes heat away; surface blood vessels widen to lose heat (vasodilation) or narrow to keep it (vasoconstriction).
   3. Answer a reveal prompt — 'Do blood vessels move to the surface?' — then check the correction: 'No — vessels near the skin widen or narrow; they don't migrate.'
   4. State why sweat cools far less on a humid day than a dry one.
3. 3

   Sort and sequence the feedback loop

   Why it works: Consolidates the cooling/warming distinction, the ordering of the feedback loop, and the enzyme rationale for a constant core temperature.

   1. Categorise responses into cooling (sweating, vasodilation) versus warming (shivering, vasoconstriction).
   2. Put the negative-feedback stages in order: stimulus → detect/receptor → control centre (brain/hypothalamus) → respond/effector → return to set point.
   3. Answer why maintaining ~37°C matters, linking it to enzyme activity and denaturation when too hot.
   4. Justify each sort by stating how that response moves heat.