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GCSE Biology · key term
The widening of blood vessels, increasing blood flow through capillaries near the skin surface.
Used by AQA, Edexcel and OCR
Specification 4.5.2.4 · Paper 2
The widening of blood vessels, allowing more blood to flow through vessels near the skin surface.
Revise: ThermoregulationMore energy can then transfer from the warm blood, through the skin, to the environment. This response is called vasodilation.
Specification 7.12B · Paper 2
Widening of the arterioles supplying skin capillaries, increasing blood flow near the skin surface and heat loss.
For vasoconstriction and vasodilation, name the arterioles supplying skin capillaries, then link their diameter to blood flow and heat loss.
Do not say that blood vessels move nearer to or farther from the skin. During vasodilation, the arterioles supplying surface capillaries widen; during vasoconstriction, they narrow.
Do not confuse vasodilation with sweating. Vasodilation increases energy transfer from warm blood at the skin, whereas sweating cools when water evaporates.
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The opposite change in the skin's blood supply is vasodilation. Arterioles supplying the skin capillaries widen, allowing more warm blood to flow close to the surface. More heat can then pass from the blood through the skin to the surroundings.
Specification B3.3b · Paper 1 (Foundation), Paper 3 (Higher)
Revise: Control of body temperatureAt the same time, vasodilation occurs. The arterioles supplying capillaries close to the skin surface widen, so more warm blood flows through these surface capillaries. This brings more energy close to the surface, increasing its transfer from the skin to the surroundings.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
The widening of arterioles supplying the skin, increasing blood flow through capillaries near the surface.
Revise: Skin and Temperature ControlAt the same time, the arterioles supplying capillaries near the skin surface widen. This is vasodilation. More warm blood flows close to the surface, increasing the transfer of thermal energy from the blood through the skin to the surroundings.
The widening of blood vessels supplying the skin, increasing blood flow near the body surface.