B5 Puberty/Menstrual Cycle

Question 1

Puberty

Answer 1

The period in which adolesecents start to develop secondary sexual characteristics.

Question 2

Explain all 4 hormones involved in the menstrual cycle

Answer 2

FSH-(follicle stimulating hormone) Produced in pituatary gland. Causes an egg to mature in one of the ovaries. In a structure called a follicle. Stimulates ovaries to produce oestrogen.
Oestrogen-Produced in ovaries. Grows lining of uterus. Stimulates release of LH and inhibits release of FSH.
LH-(Lutenising hormone) Produced by the pituatary gland. Stimulates release of an egg at day 14 ovulation.
Progesterone-Produced in the ovaries by the reamins of the follicle after ovulation. Maintains the lining of the uterus during the second half of the cycle. When the level of progesterone falls the lining breaks down. Inhibits the release of LH and FSH.

Question 2

Explain each stage of menstrual cycle

Answer 2

1-Day 1-4 Menstruation starts uterus lining breaks down.
2-Day 4-14 Uterus lining builds up again into a thick spongy layer full of blood vessels ready to receive a fertilised egg.
3-Day 14 Egg develops then released from ovary. It is called ovulation.
4-Day 14-28 Wall is maintained and if egg is not fertilised by day 28 then spongy lining starts to break down and cycle starts again.

Question 3

2 methods of hormonal contraception

Answer 3

Pills containing oestrogen and progesterone reduce fertility.Oestrogen prevents release of the eggs. Porgesterine stimuates production of mucus which prevents any sperm reaching the egg.

An injection only containing progesterone that lasts 2-3 months.

Question 4

Advantage of barrier methods

Answer 4

They prevent sexually transmitted diseases

Question 5

Pros and Cons of IVF

Answer 5

Pro-Fertility treatment can give an infertile couple a child
Cons-Multiple births can occur
Higher chance of miscarrage
Sucess rate of IVF is low
Physically stressful in reaction to hormones vomiting