4.HUMAN REPRODUCTIONBy Teresa,Claudia andLucia.

REPRODUCTION

PRIMARY SEXUAL CHARACTERISTISThe reproductive system are the

primary sexsual characteristics.We alredy have them when we

are born and they are different for male and female.

SECONDARY SEXUAL CHARACTERISTICS

The external characteristics which differentiate men from women are called secondary sexual characteristics.

During puberty between the ages of eleven and fifteen the reproductive system matures.Some physical changes are the same for both sexes, like growing taller or hair growing in the armpit.

Other changes are specific to each sex:

Girls develop breasts and their hips get wider.

Boys get deeper voices or get facial hair.

REPRODUCTIVE CELLSReproductive cells carry out the

funtion of reproduction.Sperm: are the male reproductive

cells. They have a head and a long tail called flagellum. They are produced in large numbers from the time of puberty.

Ova: are the female reproductive cells. They do not move. From puberty an ovum matures every month.

OVA SPERM

THE REPRODUCTIVE SYSTEMS .THE FEMALE REPRODUCTIVE

SYSTEM:Ovaries.Uterus.Fallopian tubes.Vagina.Vulva.

MALE REPRODUCTIVE SYSTEM Testicles Vas deferens Urethra Seminal vesicles Prostate Penis

FERTILISATION

Fertilisation occurs when an ovum and a sperm join inside the fallopian tubes and they create a single cell called zygote. The zygote goes down the fallopian tubes, it is implanted in the wall of the uterus and it becomes an embryo.

PREGNANCY AND BIRTHPREGNANCYPregnancy last about 9 months and

ends in a birth.During the early stages, different

structures are created to protect the embrio:

The placenta.The umbilical cord.The amniotic sac.

The baby develops step by step:After 3 months: the embryo has all

its organs. It becomes a foetus.After 5 months: the baby starts

moving and the mother feels it.After 9 months: the baby is ready to

be born and it weighs around 3 kilos.LABOUR

o Dilation.o Expultion.o Afterbirth.