A catering worker repeatedly moves trays from an oven for 10 minutes. The air and surrounding surfaces away from the oven are cooler than the worker's skin.
The table shows all of the energy transfers affecting the worker during this time.
| Source or route | Energy transferred during the 10 minutes in kJ\mathrm{kJ}kJ |
|---|---|
| Energy transferred as heat from respiration | 156 |
| Radiant energy transferred from the oven to the worker | 24 |
| Energy transferred from the skin by sweat evaporation | 82 |
| Energy transferred from the skin by radiation and convection | 61 |
Calculate the net energy transfer to or from the worker during the 10 minutes. Use your result to explain how a change in the arterioles supplying the skin capillaries would help return the worker's core body temperature towards its normal range.
78 exam-style questions on Edexcel GCSE Biology 7.3 Homeostasis and thermoregulation, covering 7.3.1 Importance of a constant internal environment, 7.3.2 Importance of homeostasis, 7.3.3a Thermoregulation via the skin and hypothalamus, and 7.3.3b Vasoconstriction and vasodilation in thermoregulation. Each one has a worked solution and a mark scheme showing where the marks go.