A researcher measures blood flow through equal areas of skin on the two forearms of a person. The person exercises at a constant rate in a room at 20.0 ∘C20.0\ ^\circ\mathrm{C}20.0 ∘C.
The arterioles supplying one skin region respond normally. The arterioles supplying the other region cannot dilate.
| skin region | relative skin blood flow before exercise in arbitrary units | relative skin blood flow after 12 minutes of exercise in arbitrary units | skin temperature after 12 minutes of exercise in ∘C^\circ\mathrm{C}∘C |
|---|---|---|---|
| L | 22 | 64 | 34.3 |
| R | 22 | 24 | 30.8 |
Explain which skin region is supplied by arterioles that cannot dilate and how damage of this type over a large area of skin would affect core body temperature during continued exercise.
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.