SB7g- Thermoregulation

• What is thermoregulation?

  The control of internal body temperature
• What should the core body temperature be and why?

  37 degrees Celsius because it is the optimum temperature for enzymes to function.
• Thermoregulatory centre helps with thermoregulation, and is inside the hypothalamus.
• We have receptors around our body to detect and so something about change in temperature. These are mostly in the skin and blood vessels. These send signals to the brain whether we are too hot or cold so the brain can do something.
• If the body needs to warm up

  1. Body temp falls due to cold environment
  2. Hypothalamus detects fall and causes body responses
  3. Changes triggered in blood flow so less blood flows near the skin surface ( vasoconstriction )
  4. Sweat glands stop producing sweat
  5. Body hairs raised by erector muscles in skin (goosebumps), trapping an insulating layer of air
  6. To generate heat, the body shivers as it requires energy from respiration, and heat energy is released as waste
  7. Reduces transfer of energy to surroundings (less energy is lost)
• If the body needs to cool down

  1. Body temp rises due to hot environment
  2. Hypothalamus detects rise and causes body response
  3. Changes triggered in blood flow so blood flows near skin surface ( vasodilation)
  4. Sweat glands release more sweat onto skin surface to evaporate, sebaceous glands produce oil that helps sweat spread all over skin
  5. Erector muscles relax
  6. Increases energy transfers to surroundings (Lowers body temp)
• Vasoconstriction and vasodilation changes blood flow depending on temperature through surface capillaries
• Vasoconstriction (when cold)

  • More blood flows through deep skin blood vessels so less blood flows through surface capillaries
  • This keeps warm blood deeper in the skin so less heat is transferred to the air
• Vasodilation (when hot)

  • less blood flows through deep skin blood vessels and more blood flows through surface capillaries, increasing heat loss by radiation, as heat can transfer easier to the air.