B5: The Menstrual Cycle

Question 1

What is the main reproductive hormone in women?

Answer 1

Oestrogen:
Produces by the ovaries
Brings about physical changes but is also involved in the menstruated cycle

Question 2

Explain the first stage of the menstrual cycle.

Answer 2

Day 1 - menstruation starts. The uterus lining breaks down for about four days.

Question 3

Explain stage 2 of the menstrual cycle.

Answer 3

The uterus lining build up again, from day 4 to day 14, into a thick spongy layer full of blood vessels, ready to receive a fertilised egg.

Question 4

Explain stage 3 of the menstrual cycle.

Answer 4

An egg develops and is released from the ovary at day 14 - this is called ovulation.

Question 5

Explain stage 4 of the menstrual cycle.

Answer 5

The wall is then maintained for about 14 days until day 28. Of 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 6

Explain the role of FsH in the menstrual cycle.

Answer 6

Follicle-Stimulating Hormone:
Produced in the pituitary gland
Causes an egg to mature in one of the ovaries (in a structure called a follicle)
Stimulates the ovaries to produce oestrogen

Question 7

Explain the role of Oestrogen within the menstrual cycle.

Answer 7

Produced in the ovaries
Causes the lining of the uterus to grow
Stimulates the release of LH
Inhibits the release of FSH

Question 8

Explain the role of LH in the menstrual cycle.

Answer 8

Liteinising Hormone:
Produced in the pituitary gland
Stimulates the release of an egg at day 14 (ovulation)

Question 9

Explain the job of progesterone wishing the menstrual cycle.

Answer 9

Produced in the ovaries by the remains 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