Thermoregulation pack 5

• What is thermoregulation?

  It is the process your body uses to keep its internal temperature steady.
• Why is it important for the body to maintain a steady internal temperature?

  Because enzymes in the human body work best at about 37°C.
• What happens to enzyme activity below 37°C?

  Enzyme activity decreases.
• What happens to enzymes above 37°C?

  Enzymes may start to denature and cannot work at all.
• What is the core body temperature that the body maintains?

  37°C.
• What triggers a response in the body when there is a change in temperature?

  A change in body temperature triggers a response to counteract it.
• What structure in the brain acts as the body's thermostat?

  The hypothalamus.
• What type of receptors does the hypothalamus contain?

  Receptors that are sensitive to blood temperature.
• Where are the receptors that provide information about external temperature located?

  In the epidermis and dermis of the skin.
• What happens when the hypothalamus detects a change in temperature?

  It causes a response in the skin.
• What are the responses of the body when it is too hot?

  1. Erector muscles relax, making hairs lie flat.
  2. Sweat is produced in sweat glands, cooling the body as it evaporates.
  3. Blood vessels near the surface of the skin widen (vasodilation) to allow more blood flow and energy transfer to the surroundings.
• What are the responses of the body when it is too cold?

  1. Erector muscles contract, causing hairs to stand on end and trap an insulating layer of air.
  2. Very little sweat is produced.
  3. Blood vessels near the surface of the skin constrict (vasoconstriction) to reduce blood flow and energy transfer to the surroundings.
  4. Shivering occurs, increasing the rate of respiration to generate heat.
• What is the effect of vasodilation on blood vessels when the body is too hot?

  It allows more blood to flow near the surface to transfer more energy to the surroundings.
• What is the effect of vasoconstriction on blood vessels when the body is too cold?

  It reduces blood flow near the surface, so less energy is transferred to the surroundings.
• What happens to the blood supply to the fingers during extreme cold exposure?

  The blood supply is cut off to reduce energy loss, which can lead to frostbite.
• What is the role of shivering in thermoregulation?

  • Shivering involves automatic muscle contractions.
  • It increases the rate of respiration.
  • This process generates more heat to warm the body.