Topic 7 - The Menstrual Cycle and Pregnancy

Question 1

what happens in the first stage of the menstrual cycle?

Answer 1

day 1 - menstruation starts. the uterine lining breaks down for about 4 days

Question 2

what happens in the second stage of the menstrual cycle?

Answer 2

the uterus lining builds up again from day 4 to 14, into a thick spongy layer ready to receive a fertilised egg

Question 3

what happens in the third stage of the menstrual cycle?

Answer 3

an egg develops and is released from the ovary at day 14 (ovulation)

Question 4

what happens in the fourth stage of the menstrual cycle?

Answer 4

the wall is maintained from day 14 to day 28. if no fertilised egg had landed on the uterus wall by day 28, the spongy lining starts to break down

Question 5

how does oestrogen control the menstrual cycle?

Answer 5

1. produced in the ovaries
2. causes the uterus lining to grow
3. stimulates the release of LH

Question 6

how does progesterone control the menstrual cycle?

Answer 6

1. produced in the ovaries by the remains of the follicle after ovulation
2. maintains uterus lining during the second half of the cycle. when progesterone falls the uterus lining breaks down
3. inhibits the release of LH and FSH

Question 7

what happens once the embryo has implanted?

Answer 7

the placenta develops, which lets the blood of the embryo and mother get very close to allow the exchange of food, oxygen and waste

Question 8

what is the amnion membrane?

Answer 8

it forms after the embryo has implanted. it surrounds the embryo and is full of amniotic fluid, which protects the embryo from knocks and bumps.