The menstrual cycle begins @ about 12 yrs and stops
On average it takes 28 days
It begins with menstruation (a period) which lasts
about 5 days during which time the old lining of the
uterus is removed from the body.
This lining starts to build up again and at about day
14 an egg is released from an ovary (ovulation).
The egg travels down the fallopian tubes and if
fertilised pregnancy begins
If the egg is not fertilised it dies.
At day 28 if pregnancy has not happened the egg and
uterus lining break down and the cycle begins again.
To create a baby a sperm must fertilise an egg
inside the mother.
During sexual intercourse the males penis
becomes stiff because the tissue its made from
fills with blood
It is then possible to insert it into the female
During ejaculation a liquid called semen which
contains millions of sperm are released into the
The sperm swim up through
the cervix, the uterus and
the fallopian tubes.
If an egg is in a fallopian
tube one sperm cell will
fertilise the egg.
The fertilised egg will
travel down into the womb
and stick onto the lining on
the side of the womb
Pregnancy / Gestation
Lasts 40 weeks
Egg develops into embryo
Embryo is surrounded in womb by a liquid called amniotic
The liquid is inside a bag called the amniotic sac.
Outside the sac is the placenta which filters oxygen and
food from the mothers blood for the embryo
Some harmful substances can get through the placenta
so mothers must avoid alcohol medicine, nicotine and
other drugs during pregnancy.
8 weeks after fertilisation the embryo looks more like a
baby and is then called a foetus
The foetus is connected to the placenta by the umbilical
A few days before birth , baby turns so that its
head lies next to cervix.
The walls of the womb begin to contract – labour
The membrane around baby breaks and the
amniotic fluid is released – waters break.
Contractions force baby through cervix and vagina
and out of the mother.
The final contraction pushes out the placenta
The umbilical cord is cut and clamped, after a few
days the part attached to the baby shrivels , falls
off and leaves the navel (bellybutton).