Thermoregulation

• Thermoregulation - controls our internal body temperature
• Our body is kept at 37 °C, as it the optimum temperature for enzymes.
• Thermoregulatory centre - is an area in the hypothalamus in the brain, which contains blood temperature receptors and regulates body temperature.
• How to body warms up:

  1. Constricts blood vessels which are near the surface of the skin (Vasoconstriction). So less blood flows near surface and less heat energy is lost to the surroundings.
  2. Contracts erector muscles, making out hair stand up. This traps a small layer of insulating air, which makes to harder to lose hear.
  3. Shivering (muscles contracting automatically). This requires respiration, which will release heat energy as waste.
• How our body cools down:

  1. Relaxing erector muscles, which allows hairs to lay flat.
  2. Expanding blood vessels (Vasodilate). This allows more heat energy to transfer to surroundings, as warm blood is passing closer to the skin.
  3. Sweating, as sweat evaporates it takes heat energy form our bodies, because it requires lots of energy to evaporate.
• What is vasoconstriction?

  Narrowing of blood vessels.
• What is vasodilation?


  Widening of blood vessels.
• How does vasodilation help control body temperature?

  It causes the blood vessels to widen so more warm blood will pass at the surface. So more energy will be transfer to the surroundings, therefore temperature lowers.
• How does vasoconstriction help control body temperature?

  It causes the blood vessels to narrow so less warm blood will pass at the surface. So less energy will be transferred to the surroundings, therefore temperature increases.