Flashcards in Life Science- Fertilisation And Pregnancy Deck (17):
Both male and female
Are needed to produce sexually
When man and woman have
Intercourse, the man places his erect penis inside the woman's vagina; copulation.
Semen into the vagina. Sperm swim up through the uterus and into the Fallopian tubes. If there is an ovum in one of the Fallopian tubes, the sperm fuses with the ovum to form a zygote
Fusion of sex cell
Fertilization. The first stage of pregnancy
If fertilization occurs
We say the woman has conceived
Few hours after fertilization
Zygote divides into many cells until a ball of cells is formed. While the zygote is dividing, it moves along the Fallopian tube to the uterus.
Ball of cells
Attaches itself to the spongy tissue layer of the endometrium on the uterus; implantation. Uterus holds the ball of cells securely. It won't call out unless something goes wrong with the uterus lining or cells
Once zygote has
Implanted itself into the endometrium of the uterus, a special disc-like structure forms to feed it; placenta.
Substances such as
Nutrients, oxygen and waste products move between the blood of the developing embryo and the mother in the placenta, but their blood never mixes.
Developing embryo is
Attached to the placenta by the umbilical cord
Zygote divides and
Grows into an embryo. After a few weeks the cells start to change to become muscles, bones, heart and blood vessels.
From week 8
Embryo is called a foetus. Foetus remains in the uterus until it is ready to be born
Period from fertilization to birth. Approximately 40 weeks in humans
Embryo is surrounded
By amniotic sac that is filled with amniotic fluid.
Protects the developing embryo in the uterus of the mother
As the foetus grows
It begins to kick and move, it sleeps and sucks its thumb. It can hear the mother's heart beating and the sounds of people talking. Some even have hiccups whilst in the uterus.