Control of Body Temperature

• What should the human body temperature be kept at in celsius and why?

  Around 37°C

  This gives an optimum temperature for enzymes to work
• What is the thermoregulatory centre?

  The part of the brain responsible for maintaining a constant body temperature in warm blooded animals
• What does the thermoregulatory centre in the brain do/contain?

  -monitors and controls body temperature

  -has receptors that monitor the temperature of the blood flowing through the brain

  -receives information (impulses) from temperature receptors in the skin
• What happens in the thermoregulatory centre if the body temperature is too high?

  -blood vessels widen, directing more blood to the surface of the skin

  -more sweat is produced from the sweat glands and evaporates

  -both these mechanisms cause a transfer of energy from the skin to the environment
• What is vasodilation?

  process that occurs when blood vessels in the skin become wider so that more blood flows close to the surface of the skin to increase heat loss
• What happens in the thermoregulatory centre if the body temperature is too low?

  -blood vessels narrow, directing blood away from the surface of the skin

  -sweating stops

  -skeletal muscles uncontrollably contract and relax quickly (shiver), which transfers more heat to the blood
• What is vasoconstriction?

  Process that occurs when blood vessels in the skin become narrower so that less blood flows close to the surface of the skin
• How is the brain alerted for changes in the external temperature of a person?

  Temperature receptors in the skin give the brain an early warning

  This allows behaviour to be adjusted to stop the body temperature changing
• What behaviour would a person do if their body temperature is too high?

  Taking off of clothes
• What behaviour would a person do if their body temperature was too low?

  Putting on more clothes
• How do blood vessels in the skin adjust how much energy is transferred to the outside?

  They narrow and widen since they cannot move