Question 6

Explain the role of the skin in maintaining body temperature.

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College Answer

It was expected candidates would describe that the maintenance of body temperature is a balance of heat loss and heat production and outline the series of controls that are important in this process.

An overview of the reflexes involved was expected with some comments on temperature receptors in skin for hot and cold, the hypothalamic integration and then the effector being skin blood flow (vasodilation / vasoconstriction and A-V shunts).

Answers were expected to include some comment on the fact that heat exchange occurs via radiation / conduction / convection/evaporation and requires a heat gradient and that skin blood changes can facilitate or impair this exchange. Using examples such as; if body needs to loose heat there is vasodilation and sweating often added clarity. Extra credit was given for discussing sweat production and the principle of how that will allow increased heat loss with further credit given for discussing the impact of humidity.

Credit was also given for mentioning piloerection, particularly if candidates went on to explain why this might be useful (even though not really applicable in man).