Controlling body temperature

• Body temperature should be around 37°C,the optimum temperature for enzymes
• The body has to balance the amount of energy gained and lost to keep the core body temperature constant
• There is a thermoregulatory center in the brain, which contains receptors that are sensitive to the temperature of the blood flowing through the brain
• The thermoregulatory centre also receives impulses from temperature receptors in the skin, giving information about skin temperature.
• Temperature receptors detect that core body temperature is too low/high.
• The thermoregulatory centre acts as a co-ordination centre- it receives information from the temperature receptors and triggers the effectors automatically.
• Effectors produce a response and counteract the change. This might be muscles or sweat glands.
• Some effectors work antagonistically e.g. one effector heats and the other one cools

  - they’ll work at the same time to achieve a very precise temperature. This mechanism allows a more sensitive response.
• Vasodilation happens when you‘re too hot
• Vasoconstriction happens when you’re too cold
• When you’re too cold , no sweat is produced and hair stands on end to trap an insulating layer of air next to the skin.
• In vasoconstriction, blood vessels supplying skin capillaries constrict to shut off the skins blood supply
• When you‘re too cold, shivering occurs from automatic muscle contraction. This needs respiration, which transfers some energy to warm the body.
• When you’re too hot, sweat is produced by sweat glands and evaporates from the skin. This transfers energy to the environment.
• During vasodilation, the blood vessels supplying the skin dilate so more blood flows closer to the surface of the skin. This helps transfer energy from the skin to the environment.