Body temperature

• The thermoregulatory centre contains receptors sensitive to changes in temperature
• We shiver when we’re cold because

  The contractions of the muscles release heat energy to warm the body
• When the body becomes too cold, blood is diverted from the limbs to the core to decrease heat loss
• Receptors in the thermoregulatory centre of the brain directly monitor changes in temperature of the blood
• Where is the thermoregulatory centre

  The brain
• How is temperature monitored by the body

  Skin has receptors sensitive to skin temperature
• Why does the temperature near the brain decrease when cold water is drank

  Blood is cooled at the stomach

  Blood flows to the brain
• The thermoregulatory centre sends information via neurones
• Water is lost from the skin through sweating
• The body needs to lose water from the skin to maintain body temperature
• Sweating helps to control body temperature by cooling us down
• What changes happen when body temperature is too high

  Vasodilation

  • Blood vessels dilate

  Sweating increases - you lose more heat through the skin

  Less blood flow through capillaries

  Less energy is lost to the surroundings
• Water, ions and urea are lost from the skin when we sweat
• What changes happen when body temperature is too low?

  Vasoconstriction

  Blood vessels constrict

  Sweating stops, shivering starts - skeletal muscles contract