Homeostasis & Response

Question 1

A scientist investigated the effect of drinking ice-cold water on:
* internal body temperature
* the rate of sweating.
The results show that when the ice-cold water was drunk, the temperature near the brain decreased.
Explain why the temperature near the brain decreased. [2 marks]

Paraphrased from June 2021 paper 2. Got 1/2 marks in the Easter holiday.

Answer 1

• blood is cooled at stomach / mouth
• (cooled) blood flows to the brain

Question 2

The thermoregulatory centre in the brain responds to a decrease in temperature.
How does the thermoregulatory centre send information to sweat glands in the skin? [1 mark]

Answer 2

via nerve(s) / neurones
or
via (nerve) impulse(s)
allow electrical signals
allow via the nervous system

ignore type of neurone

Question 3

How is body temperature monitored and controlled?

Answer 3

With the thermoregulatory
centre in the brain.

Question 4

Define vasodilation.

Answer 4

The widening of blood vessels.

Question 5

What causes the skin to appear red during exercise? [1 mark]

In paper 2 of June 2021, this was a multiple choice question. Got 0/1 marks in the Easter holiday.

Answer 5

The dilation of blood vessels in the
skin.

Question 6

Reflex actions are coordinated by the nervous system.
What is meant by the term ‘reflex action’? [2 marks]

Got 1/2 marks in the Easter holiday.

Answer 6

response / reaction
automatic or no thinking or not conscious or involuntary

ignore examples
ignore action
ignore reference to brain
ignore quick

Question 7

Describe how hormones control the menstrual cycle. [5 marks]

Got 3/5 marks in the Easter holiday.

Answer 7

FSH (release from pituitary) stimulates maturation of egg / ovum / follicle
allow FSH stimulates development / growth of egg

oestrogen (release from ovary) inhibits FSH production and stimulates LH production

LH (release from pituitary) stimulates ovulation
allow LH stimulates release of egg

progesterone (release from ovary) inhibits FSH and LH production
allow (release from corpus luteum)

oestrogen and progesterone maintain the uterus lining
allow oestrogen and progesterone build up the uterus lining

ignore reference to days of menstrual cycle