New life

© PDST Home Economics

New Life A baby begins

as a single cell within a mother.

The cell forms when an egg (ovum) from the mother is fertilized by a sperm from the father

Female reproductive System Ovaries Fallopian

tubes Uterus

(Womb) Cervix Vagina

Menstrual Cycle The menstrual cycle begins @ about 12 yrs and

stops about 55yrs 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.

Menstrual Cycle

Male Reproductive System

Testes Scrotum Sperm ducts Penis

Sexual Intercourse

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 vagina.

During ejaculation a liquid called semen which contains millions of sperm are released into the females vagina

Fertilisation 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. (fertilisation, conception)

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 fluid 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 cord

Pregnancy / Gestation

Birth A few days before birth , baby turns so that its

head lies next to cervix. The walls of the womb begin to contract –

labour pains. 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

(afterbirth). 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).

Birth