Controlling Body Temperature

• Body temperature


  Optimum temperature for enzymes in the body, around 37°C
• Keeping body temperature constant

  Balancing energy gained (e.g. through respiration) and energy lost
• Thermoregulatory centre


  • Located in the brain
  • Contains receptors sensitive to temperature of blood flowing through the brain
  • Receives impulses from temperature receptors in the skin
• Core body temperature


  Temperature inside the body, where internal organs are
• Body temperature control via negative feedback

  1. Temperature receptors detect temperature change

  2. Thermoregulatory centre receives information and triggers effectors

  3. Effectors produce a response to counteract the temperature change
• Antagonistic effectors


  • One effector heats, another cools
  • Work together to achieve precise temperature control
  • Allows more sensitive response
• Responses to being too hot

  1. Hairs lie flat

  2. Sweat is produced and evaporates, transferring energy to environment

  3. Blood vessels dilate, increasing blood flow to skin surface
• Responses to being too cold

  1. Hairs stand up to trap insulating air

  2. No sweat is produced

  3. Blood vessels constrict, reducing blood flow to skin

  4. Shivering, which transfers energy to warm the body