SB7: Animal Coordination, Control And Homeostasis

Question 1

What are hormones?

Answer 1

Chemical molecules released directly into the blood to regulate bodily processes / chemical messengers that travel in the blood to activate cells in target organs

Question 2

Name six endocrine glands of the body

Answer 2

• pituitary gland
• thyroid gland
• pancreas
• adrenal glands
• ovaries
• testes

Question 3

Explain why the pituitary gland is known as the ‘master‘ gland

Answer 3

It produces many hormones that regulate the body and many of the hormones act on other glands to stimulate production of other hormones

Question 4

What does thyroxine (the hormone produced by the thyroid gland) regulate?

Answer 4

Rate of metabolism, heart rate and temperature

Question 5

What is the role of insulin in the body?

Answer 5

To regulate the blood glucose level

Question 6

Name the response that adrenaline is involved in

Answer 6

The ‘fight or flight‘ response

Question 7

State what oestrogen (the hormone released by the ovaries) controls

Answer 7

Menstrual cycle

Question 8

State what testosterone (the hormone released by the testes) controls

Answer 8

Puberty and sperm production in males

Question 9

Compare the differences between nerves and hormones

Answer 9

HORMONES
- slower acting
- act on the body for a long time 
- act in a more general way
NERVES
- fast acting
- act for only a short time 
- act on a very precise area

Question 10

Name the hormone whose release is stimulated by the sex hormones

Answer 10

Growth hormone

Question 11

Where does the growth hormone stimulate cells to divide?

Answer 11

Muscles and bones

Question 12

What does the growth hormone stimulate the digestive system to do?

Answer 12

Absorb calcium ions used to make strong bones

Question 13

Name the four hormones produced by the pituitary gland

Answer 13

• ACTH
• FSH
• LH
• growth hormone

Question 14

Use a flowchart to describe how a change in the amount of sex hormone produced during puberty in females leads to an increase in growth

Answer 14

Ovaries secrete more oestrogen into the circulating blood —> oestrogen stimulates pituitary gland to release greater amounts of growth hormone —> growth hormone stimulates muscle and bones to increase the rate of cell division (rate of growth)

Question 15

What happens when your brain detects danger or stress?

Answer 15

Brain sends nerve impulses to the adrenal glands

Question 16

What does adrenaline increase the supply of to cells?

Answer 16

Oxygen and glucose

Question 17

What is caused by adrenaline binding to specific receptors in the heart?

Answer 17

Heart muscle contracts with more force and frequency

Question 18

What does adrenaline binding to specific receptors in the heart (casing the heart muscles to contract with more force and frequency) increase?

Answer 18

Heart rate and blood pressure

Question 19

What do muscle cells receive more of due to the increased blood flow to them?

Answer 19

More oxygen and glucose

Question 20

Why do muscle cells need more oxygen and glucose?

Answer 20

Increased respiration for muscle contraction

Question 21

What is caused by adrenaline binding to receptors in the liver?

Answer 21

Liver breaks down glycogen stores into glucose which is released into the blood

Question 22

What does adrenaline binding to receptors in the liver do to the blood glucose level?

Answer 22

Increases it

Question 23

Explain why it is important for adrenaline to bind to receptors in the liver to happen during the ‘fight or flight‘ response

Answer 23

To fuel respiration in the muscle cells for contraction

Question 24

Describe what happens to blood vessels leading to muscles when the amount of adrenaline in the blood is increased

Answer 24

The diameter of the blood vessels widens

Question 25

Explain why the diameter of blood vessels leading to muscles widens when the amount of adrenaline in the blood increases

Answer 25

To increase blood flow to muscles

Question 26

Describe what happens to blood vessels leading to other organs (eg. the stomach) when the amount of adrenaline in the blood increases

Answer 26

The diameter of the blood vessels narrows

Question 27

Explain why the diameter of blood vessels leading to other organs narrows when the amount of adrenaline in the blood increases

Answer 27

To decrease the blood flow to the other organs and increase overall blood pressure

Question 28

Name three target organs of adrenaline

Answer 28

• heart
• liver
• blood vessels
  (Also the brain, eyes - pupil dilation)

Question 29

Name some processes that require the transfer of energy when the body is fully at rest

Answer 29

Any life process that is continuous and essential for life, such as:

• breathing
• conducting impulses by neurones (eg. in the brain)
• heart beating
• glands making hormones
• organs responding to hormones