Controlling body temperature

• the thermoregulatory centre monitors and regulates body temperature
• the thermoregulatory centre is found in the hypothalamus
• the thermoregulatory centre contains receptors, it also recieves nervous impulses from temperature receptors in the skin
• What should you be able to describe by the end of the video?

  How the brain monitors body temperature and how the body responds to temperature changes
• What is homeostasis?

  Homeostasis keeps all of the body's internal conditions relatively constant
• What is the normal human body temperature?

  37 degrees Celsius
• How is body temperature monitored and controlled?

  By the brain, specifically the thermo regulatory center
• What is the function of the thermo regulatory center?

  It contains receptors sensitive to the temperature of the blood
• What type of neurons send electrical impulses to the thermo regulatory center?

  Sensory neurons
• What happens when body temperature gets too high?

  The body sweats and blood vessels dilate
• How does sweating help cool the body down?

  Evaporation of sweat takes energy from the body, cooling it down
• What is vasodilation?

  It is the widening of blood vessels supplying the capillaries
• What happens to blood flow during vasodilation?

  More blood flows through the capillaries
• How does the body respond when the temperature drops too low?

  Blood vessels constrict and the body shivers
• What is vasoconstriction?

  It is the narrowing of blood vessels supplying the capillaries
• What happens to heat loss when blood vessels constrict?

  Less heat is lost from the body
• How does shivering help warm the body?

  It generates heat through muscle contractions
• What happens to the rate of respiration during shivering?

  The rate of respiration increases
• What do we stop doing when body temperature falls too low?

  We stop sweating
• What is the process of how the body responds to high temperature?

  1. Sweat glands produce sweat
  2. Sweat evaporates, cooling the body
  3. Blood vessels dilate (vasodilation)
  4. More blood flows through capillaries
  5. Heat transfers out of blood
• What is the process of how the body responds to low temperature?

  1. Blood vessels constrict (vasoconstriction)
  2. Less blood flows through capillaries
  3. Heat loss is reduced
  4. Shivering occurs to generate heat
  5. Respiration rate increases to release heat
• How does the thermo regulatory center maintain homeostasis?

  • Detects changes in body temperature
  • Initiates responses to restore normal temperature
  • Coordinates sweating, blood vessel dilation/constriction, and shivering
• How do the responses to high and low body temperatures illustrate homeostasis?

  • Both responses aim to return body temperature to 37 degrees Celsius
  • Involve different mechanisms: sweating and vasodilation for high temperatures; shivering and vasoconstriction for low temperatures