Presentación sobre la reproducción humana para alumnos de 6º de primaria

1. Human reproduction
Human reproduction is part of the interaction function.
It has certain characteristics:
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Human reproduction is sexual: It involves two individuals.
Human fertilization is internal: it takes place inside the female
reproductive system.
Humans are viviparous creatures because the embryo development
takes place in the mothers womb.

2. Sexual reproduction
Our reproduction is sexual because two individuals are involved.
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The male has male reproductive organs (testicles) which produce
male gametes (sperm)
The female has female reproductive organs (ovaries) which produce
female reproductive gametes (ovules)

3. Fertilization
It is the union of a male gamete (sperm) and a female gamete
(ovule).
In humans, this fertilization is internal: it takes place inside the
female reproductive system, in the fallopian tubes.
The union of an ovule and a sperm is what we call zygote.

4. Fertilization.

5. Embryo development
Human embryo development is viviparous because it is carried in
the mother's womb.

6. Embryo development
The zygote leaves the fallopian tube and goes to the uterus. It gets
stuck to the wall and starts growing there.
It is now called embryo.
The embryo remains in the mother's womb for about nine months.

7. Gestation
It is the time the embryo remains in the mothers womb for nine
months.
We divide this period into three trimesters.

8. First trimester.
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The embryo is surrounded and protected by a sack full of liquid, the
amnion.
The embrio produces and organ called placenta. This placenta
extracts nutrients and oxygen from the mother's blood.
These oxygen and nutrients reach the embryo through a conduct:
the umbilical cord.

9. First trimester.

10. Second trimester.
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The embryo is called now a foetus.
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The skelleton, musculature and organs develope.

11. Third trimester.
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At the end of the seventh month, all the foetus' organs are already
sufficiently developed for it to survive outside the mother.
From this moment until the ninth month it gains weigh and fits the
head into the neck of the uterus. It is ready to be born.

12. Childbirth
When the baby is ready, the muscles of the uterus produce
contractions.
The amnion breaks and the baby comes out of the vagina.
The umbilical cord is cut.
The remains of the cord leave a scar on the abdomen of the baby:
the navel.

13. Childbirth