Hormones

Question 1

What is a hormone?

Answer 1

Chemical molecules released directly into blood, they control things in organs and cells that need constant adjustment

Question 2

What is the endocrine system?

Answer 2

A group of glands that produce the hormones used in our body

Question 3

Blood glucose is controlled by what two hormones?

Answer 3

Insulin and glucagon

Question 4

If the blood glucose level is too high….

Answer 4

Insulin is secreted by the pancreas
Insulin makes the liver turn glucose into glycogen
Therefore there’s less glucose in the blood and the glucose levels fall

Question 5

If blood glucose levels are too low…

Answer 5

Glucagon is secreted by the pancreas
Glucagon forces liver to break down glucagon into glucose and release it
This means more glucose is in the blood so blood glucose levels rise

Question 6

With type one diabetes the pancreas produces…

Answer 6

Little or no insulin meaning their blood glucose levels could get to a level that could kill them. Therefore they need insulin injections throughout the day to ensure glucose is removed from their body

Question 7

With type two diabetes a person becomes….

Answer 7

Resistant to their own insulin (insulin is still produced, their body cells just don’t respond properly to the hormone), this could cause their blood glucose levels to rise very very high.

Question 8

How can oestrogen be used to reduce fertility?

Answer 8

They can prevent the release of an egg so can be used as contraception. This is because it stops the production of FSH so after a while egg development and production stop

Question 9

What is the pill?

Answer 9

A contraceptive containing oestrogen and progesterone.

Question 10

What does FSH do?

Answer 10

Produced in the pituitary gland
Causes egg to mature
Stimulates ovaries to produce oestrogen

Question 11

What does oestrogen do?

Answer 11

Produced in ovaries
Causes lining of uterus to grow
Stimulates release of LH and inhibits release of FSH

Question 12

LH

Answer 12

Produced by pituitary gland
Stimulates release of egg

Question 13

Progesterone

Answer 13

Produced in ovaries
Maintains lining of uterus during second half of cycle, when progesterone levels falls the lining breaks down

Question 14

What is thyroxine?

Answer 14

It is responsible for regulating the growth and brain development of young animals
Regulates the rate of metabolism, heart rate and temperature

Question 15

What happens when the concentration of thyroxine is too high in the blood:

Answer 15

It is detected by the pituitary gland meaning less TSH is released - this causes the secretion of thyroxine from the thyroid gland to slow bringing the thyroxine level in the blood to return to normal

Question 16

What happens if the concentration of thyroxine is too low?

Answer 16

• lack of thyroxine is detected by the pituitary gland
• pituitary gland releases TSH
• TSH stimulates the thyroid gland to release more thyroxine
• this causes the levels to rise

Question 17

What does adrenaline do?

Answer 17

• prepares body for action when in shock, under stress or threatened in some way
• enlarges air passages of lungs to allow more oxygen and glucose to be delivered to muscles and brain
• dilates pupils
• increases heart rate

Question 18

Are insulin injections a useful treatment for type 2 diabetes?

Answer 18

No

Question 19

What is the menstrual cycle?

Answer 19

A monthly cycle which involves the maturation and release of an egg

Question 20

What happens in stage one of the menstrual cycle?

Answer 20

The uterus lining breaks down for about four days

Question 21

What happens in stage two of the menstrual cycle?

Answer 21

The uterus lining builds up again from day 4 to day 14, into a thick spongy layer full of blood vessels

Question 22

What happens in stage 3 of the menstrual cycle?

Answer 22

Ovulation happens - an egg develops and is released from the ovary at day 14

Question 23

What happens at stage 4 of the menstrual cycle?

Answer 23

The uterus wall is maintained until day 28. If no fertilised egg has landed on the uterus wall by day 28, the spongy lining starts to break down and the whole cycle starts again

Question 24

How does the contraceptive patch work?

Answer 24

It contains oestrogen and progesterone and is stuck on the skin. Each patch lasts one week

Question 25

How does the contraceptive implant work?

Answer 25

It is inserted under the skin and continuously releases progesterone which inhibits the release of FSH and LH causing no egg to be released. Implant lasts for 3 years

Question 26

How does the contraceptive injection work?

Answer 26

It contains progesterone. Each dose lasts 2 to 3 months

Question 27

What does the fertility drug contain?

Answer 27

FSH and LH because some women’s natural levels of FSH are too low to cause their eggs to mature. This means no eggs are released and the women can’t get pregnant

Question 28

Pros of the fertility drug?

Answer 28

Helps women get pregnant when it doesn’t always work

Question 29

Cons of the fertility drug?

Answer 29

• it doesn’t always work - some women may have to do it many times which can be expensive
• too many eggs could be stimulated resulting in unexpected multiple pregnancies (e.g. triplets)

Question 30

Why are some people against IVF?

Answer 30

• it often results in unused embryos being destroyed (people think this is unethical because each embryo is a potential human life)
• the genetic testing of embryos before implantation raises ethical issues as people think it could lead to the selection of preferred characteristics e.g. eye colour