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edits
Changes
Skin
,→Key Stage 4
: The [[skin]] is a physical barrier to prevent [[infection]] by [[pathogen]]s.
: The [[skin]] is used in [[thermoregulation]].
When the [[Body Temperature|body temperature]] is too high:
*[[Sweat Gland|Sweat glands]] on the [[skin]] [[secrete]] [[sweat]] which [[evaporate]]s from the [[skin]] cooling it down.
*[[Erector Muscle|Erector muscles]] relax allowing the body hairs to lie flat on the [[skin]].
*[[Blood Vessel|Blood vessels]] near the surface of the [[skin]] [[dilate]] to allow more of the warm [[blood]] to pass its [[Thermal Energy Store|thermal energy]] on to the [[skin]].
When the [[Body Temperature|body temperature]] is too low:
*[[Sweat Gland|Sweat glands]] stop [[secrete|secreting]] [[sweat]] and the [[skin]] becomes dry.
*[[Erector Muscle|Erector muscles]] contract causing body hairs to stand on end. This creates a pocket of trapped air under the hairs which insulates the body.
*[[Blood Vessel|Blood vessels]] near the surface of the [[skin]] [[constrict]] reducing [[blood]] flow close to the [[skin]] preventing [[Thermal Energy Store|thermal energy]] being lost to the [[skin]].
==Beyond the Curriculum==
{{#ev:youtube|https://www.youtube.com/watch?v=OxPlCkTKhzY}}