topic 7 - homeostasis

Question 1

Describe how thermoregulatory mechanisms are controlled to help marathon runners avoid
heat stress.

Answer 1

• thermoreceptors in hypothalamus detect increase in temp
• thermoregulatory centre in hypothalamus stimulated
• hypothalumus sends impulse to sweat glands
• shunt vessels vasodilate
• decreased metabolic rate

Question 2

explain the role of the brain in reducing the students heart rate after exercise

Answer 2

• chemoreceptors in hypothalamus detect increase in PH/ decrease in CO2
• cardiac control centre receives impulse from chemoreceptors and sends signal to the SAN
• impulse is sent along parasympathetic nerve to reduce heart rate