1. 1
   A student exercises vigorously in a hot classroom and their core body temperature rises to 38.5°C.

   (a)

   The thermoregulatory centre, which monitors and controls body temperature, is located in which organ?

   [1 mark]

   • AThe brain
   • BThe pancreas
   • CThe liver
   • DThe adrenal gland

   (b)

   Which of the following responses helps to cool the student's body once their core temperature rises above normal?

   [1 mark]

   • AVasoconstriction of blood vessels supplying the skin
   • BShivering of skeletal muscles
   • CVasodilation of blood vessels supplying the skin
   • DRelease of adrenaline from the adrenal glands

   (c)

   Explain how vasodilation of the blood vessels supplying the student's skin helps to lower their body temperature.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A hiker is exposed to very cold conditions on a mountain. Their skin becomes pale and they begin to shiver.

   (a)

   Which term describes the narrowing of blood vessels supplying the skin, which occurs in these conditions?

   [1 mark]

   • AVasodilation
   • BVasoconstriction
   • COsmosis
   • DDiffusion

   (b)

   Shivering helps to increase the hiker's body temperature because it...

   [1 mark]

   • ADecreases muscle contraction
   • BReduces blood flow to the skin
   • CIncreases sweat production
   • DIncreases the rate of respiration in muscles, releasing more heat

   (c)

   Explain how vasoconstriction helps to reduce heat loss from the hiker's body in cold conditions.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A doctor is investigating a patient whose core body temperature rose to 39.2°C during a fever, then gradually returned to 37.0°C over several hours as the body responded.

   (a)

   Using the terms receptor, coordination centre and effector, describe how the patient's body detects and responds to this rise in core temperature.

   [3 marks]

   (b)

   Sweating was one mechanism that helped to reduce the patient's core body temperature during their fever. Explain, in detail, how sweating lowers body temperature, and why this response decreases once body temperature returns to normal.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A marathon runner's core body temperature rises significantly during a race in hot weather. Afterwards, the runner moves indoors into a cold, air-conditioned room, and their body must respond again to prevent their temperature falling too low.

   (a)

   Explain in detail how the runner's body responds to bring core temperature back down towards normal, referring to the roles of the thermoregulatory centre, blood vessels and sweat glands.

   [6 marks]

   (b)

   The runner then moves into a cold, air-conditioned room. Explain how the body responds to prevent core temperature falling too low in these cold conditions, and explain why this overall temperature control system is described as a negative feedback mechanism.

   [6 marks]

   Total for question 4: 12 marks

End of questions