Human reproduction by Aadriana Elena Zahira and Rebeca
PRYMARY SEXUALCHARACTERISTICSThe reproductive systems are the primary sexual characteristics . We are alredy have them when we are born and they are different for male and female
SECONDARY SEXUALCHARACTERISTICSThe external characteristics which differentiate men from woman are called secondary sexual characteristics. During puberty , between the ages of eleven and fifteen , the reproductive systems matures . Other changes are specific to each sex :*Girls develop breasts and their hips get wider.*Boys get deeper voices.
REPRODUCTIVE CELLS Reproductive cells carry out the funtion of reproduction *Sperm are the male reproductive cells.They are small.They have head and a long tail called a flagellum.They are produced in large numbers from the time of the puberty. *Ova are the female reproductive cells.They do not move.From puberty,an ovum matures every month.
THE REPRODUCTIVE SYSTEMThe female reproductive system -The ovaries -The uterus -The fallopian tubes -The vagina -The vulva
THE REPRODUCTIVE SYSTEMSThe male reproductive system:-The testicles-The vas deferens-The urethra-The seminal vesicles and prostate-The penis
FERTILISATIONFertilisation occurs when an ovum and a sperm join inside the fallopian tubes and they create 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 BIRTHPregnancy lasts about 9 months and ends in a birth. During the early stages, different structures are created to protect the embryo. *The placenta *The umbilical cord *The amniotic sac
AFTER... The baby develops step by step:*After 3 months:the embryo has all its organs.It becomes a foetus.* After 5 months:the baby´s body develops and it starts moving and the mother feels it.*After 9 months:the baby is ready to be born and it weighs around 3 kilos.
LABOURThe process of giving birth is called labour. Labour takes place in three phases:*DILATION : rhythmic contractions makethe opening of the vagina and vulva big enough for the baby to come out.*EXPULSION : The baby is born and the doctors cut the umbilical cord.*AFTERBIRTH : the placenta comes out of the mother’s body.