Primary sexual characteristicsThe reproductive systems are the primary sexual characteristics. We already have them when we are born and they are different for male and female.
Secondary sexual characteristicsThe external characteristics which differentiate men from women are called secondary sexual characteritics.During puberty between the ages of eleven and fifteen, the reproductive system matures.Other changes are specific to each sex: Girls develop breasts and their hips get wider. Boys get deeper voices.
Reproductive cellsReproductive cells carry out the funtion of reproduction. Sperm are the male reproductive cells. They are small. They have a head and a long tail called a flagellum. Ova are the female reproductive cell. They do not move. From puberty, an ovum matures every month.
The female reproductive systemThe female reproductive system is made up of these organs: The ovaries produce the ova. The uterus is where the baby develops. The Fallopian tubes connect the ovaries to the uterus. The vagina connects the uterus to the outside of the body. The vulva is the external part of the female reproductive system.
The male reproductive systemThe male reproductive system is made up of these organs: The testicles are outside the body. They produce sperm. They are covered by a bag of skin called the scrotum. The vas deferences take sperm from the testicles to the urethra. The urethra takes the sperm outside the body. The seminal vesicles and prostate produce seminal fluid and send it to the urehtra. The penis is outside the male reproductive system.
FertilisationFertilisation occurs when an ovum and a sperm join inside the Fallopian tubes and they create a single cell called a zygote. The zygote goes down the Fallopian tubes, it is implanted in the wall of the uterus and it becomes an embryo.
PregnancyPregnancy lasts about 9 months and ends in a birth.During the early stages, different structures are create to protect the embryo. The placenta takes nutrients and oxygen from the mother’s blood to the embryo. The umbilical cord connects the embryo to the placenta. The amniotic sac protects the embryo.
The baby develops step by step: Afther 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:1. Dilation: rhythmic contractions make the opening of the vagina and vulva big enough for the baby to come out.2. Expulsion: the baby is born and the doctor cuts the umbilical cord.3. Afterbirth: the placenta comes out of the mother’s body.