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1.11 gather, process and analyse information from secondary sources and use available evidence to develop a model of a feedback mechanism

gather, process and analyse information from secondary sources and use available evidence to develop a model of a feedback mechanism

Background

The body has some effective mechanisms to alter body temperature. To reduce temperature, heat can be expelled by sweating or radiation of heat from the skin. To increase heat, the body can respond by shivering or by contracting the skin. These responses can be activated by heat receptors. If a mechanism is activated, it will operate until receptors indicate that the optimum temperature has been reached.

If receptors in the skin detect heat, they relay information via the nerves to the hypothalamus, which also contains receptors sensitive to the heat of passing blood. This triggers the sympathetic nervous system to dilate skin capillaries and activate sweat glands. When receptors in the skin detect a low temperature, a negative feedback mechanism is activated to stop the original action. If skin temperature is still low, the hypothalamus may activate thyroid hormones to increase metabolic rate, activate the sympathetic nervous system to shut down skin capillaries and sweat glands and activate food metabolism in the liver to produce heat. In this way, the body can maintain a stable body temperature.