Thermoregulation

• What is thermoregulation?

  Control of our internal body temperature
• What is the optimum temperature for enzymes to work?

  37°C
• What happens to enzymes if the temperature falls below 37°C?

  Enzymes will become rigid
• What occurs to enzymes if the temperature rises above 37°C?

  Enzymes denature
• How does the body maintain a temperature of 37°C?

  • Thermoregulatory centre in hypothalamus
  • Acts as a thermostat
  • Receptors in blood vessels and skin send temperature information
  • Brain detects if the body is too hot or cold
• What is the role of the thermoregulatory centre?

  Acts as a thermostat for our body
• Where are the receptors that send temperature information located?

  In blood vessels and skin
• What happens when the body is too hot?

  Brain sends signals to cool us down
• What mechanisms does the body use to warm itself up?

  • Vasoconstriction: constricts blood vessels near skin
  • Body hairs: contract erector muscles to trap insulating air
  • Shivering: muscles contract to generate heat
• What is vasoconstriction?

  Constricting blood vessels near the skin
• What is the effect of vasoconstriction on heat loss?

  Reduces heat energy loss to surroundings
• How do body hairs help in thermoregulation?

  Traps a layer of insulating air
• What is shivering?

  Muscles automatically contract to generate heat
• How does the body cool itself down?

  • Vasodilation: expands blood vessels
  • Sweating: releases water and salts onto skin
  • Erector muscles relax, allowing hairs to fall
• What is vasodilation?

  Expanding blood vessels to release heat
• What happens to the erector muscles when the body cools down?

  Erector muscles relax, allowing hairs to fall
• What is the purpose of sweating?

  To cool the body through evaporation
• How does sweat help in cooling the body?

  Evaporation of sweat removes heat energy
• What is the energy requirement for sweat evaporation?

  Requires energy to evaporate water
• What happens to heat during sweat evaporation?

  Heat is lost from the body