Topic 7B - Exercise

Question 1

EQ. A gymnast was offered keyhole surgery to repair her damaged cruciate ligament. Suggest and explain two reasons why she might choose this type of surgery

Answer 1

• smaller incision reduces recovery time

- reduces risk of infection

Question 2

EQ. Explain how increased sweating is involved in the regulation of body temperature. (3 marks)

Answer 2

• sweat takes heat energy from the blood
• water evaporates
• taking the heat energy with them

Question 3

EQ. Explain how the extensor and flexor muscles bring about movement of the lower leg. (2 marks)

Answer 3

• work as an antagonistic pair

- when the extensor contracts, it pulls on the tibia bone to extend the leg

Question 4

EQ. Describe how thermoregulatory mechanisms are controlled to help marathon runners avoid heat stress. (4 marks)

Answer 4

• thermoreceptors detect an increase in temperature
• impulses are sent to the thermoregulatory centre in the hypothalamus
• vasodilation causes an increase to the blood flow to the surface of the skin
• signal are sent to the sweat glands to increase sweat to lose heat