© 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 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