B11 The Menstrual Cycle & Fertility

Not yet including side effects of contraception. useful Menstrual Cycle animation: https://schools-assets.abpi.org.uk/html-and-swf/2563.html

Label

The cycle:

what happens at days

1-5

5-10

14

15-28

1-5: Uterus lining breaks down, menstruation

5-10: Lining thickens again

14: Egg released, ovulation

15-28: Lining maintained

FSH and LH produced in

Pituitary gland

Oestrogen and Progesterone produced in

Ovaries

Order of hormone peaking

FOLP:

FSH

Oestrogen

LH

Progesterone

the first hormone is …

and its job is to …

it has a knock on effect …

FSH

it stimulates an egg to mature

and stimulates oestrogen release in ovary

2nd hormone is …

it does …

and has a knock on effect in that …

Oestrogen

builds uterus lining

Stops FSH, Starts LH

3rd hormone is..

it does…

LH

stimulates ovulation

4th hormone is …

it does …

knock on effect …

Progesterone

stimulates growth of uterus lining and its blood supply

stops FSH and LH

3 methods of hormonal contraception

Oral: pill with oestrogen and/or progesterone to inhibit FSH production so eggs can’t mature

Injection/Implant/Patch: slowly release progesterone so eggs can’t mature

Intrauterine device: slowly release progesterone so eggs can’t mature

up to 5 methods of non hormonal contraception

barrier: condom, diaphragm

spermicidal agents: kill or disable sperm

surgical: F = clips, M = vasectomy

Intrauterine device: prevents implantation of embryo

and Abstaining, either all the time or just when egg is in fallopian tube

Artificial Fertility

Causes of infertility: 2 for each gender

F: ovaries not releasing eggs,

blocked fallopian tubes,

problems with uterus lining

M: Poor quality sperm,

Low sperm count,

Blocked or damaged tubes which carry sperm

Fertility drugs can help …

they usually contain …

because …

for women who don’t produce an egg every month.

usually FSH

to tell the ovary to get an egg ready and produce oestrogen

Order of IVF

1. Fertility drug (FSH) given, eggs mature

2. eggs taken away

3. sperm prepared

4. egg fertilised in lab

5. embryo develops in lab

6. embryo transferred through a cannula (like big syringe)

7. embryo develops further inside woman

2 Advantages of IVF

• allows almost all women to have biological children

• less surgery for women having problems conceiving

• multiple births possible

2 disadvantages of IVF

• Doesn’t always work, low success rates

• very expensive

• ethical issues with possible discarding/destroying of embryos

• physically and emotionally stressful