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O Período Fetal (8 semanas até o Nascimento)
Capítulo 37 9 Semanas: Engole, Suspira e se Estica
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| The fetal period continues
until birth.
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| By 9 weeks,
thumb sucking begins
and the fetus can swallow
amniotic fluid.
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| The fetus can also grasp
an object,
move the head forward
and back,
open and close the jaw, move
the tongue, sigh, and stretch.
Nerve receptors in the face,
the palms of the hands,
and the soles of the feet
can sense light touch.
"In response to a light touch
on the sole of the foot,"
the fetus will bend the hip
and knee and may curl the toes.
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| The eyelids are now
completely closed.
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| In the larynx, the appearance
of vocal ligaments
signals the onset
of vocal cord development.
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| In female fetuses,
the uterus is identifiable
and immature reproductive cells,
called oogonia,
are replicating within
the ovary.
External genitalia begin
to distinguish themselves
as either male or female.
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Capítulo 38 10 Semanas: Revira os olhos e Boceja, Unhas e Impressões Digitais
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| A burst of growth
between 9 and 10 weeks
increases body weight
by over 75%.
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| By 10 weeks, stimulation
of the upper eyelid
causes a downward
rolling of the eye.
The fetus yawns and often opens
and closes the mouth.
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| Most fetuses suck
the right thumb.
Sections of intestine
within the umbilical cord
are returning
to the abdominal cavity.
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| Ossification is underway
in most bones.
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| Fingernails and toenails
begin to develop.
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| Unique fingerprints appear
10 weeks after fertilization.
These patterns can be used for
identification throughout life.
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Capítulo 39 11 Semanas: Absorve Glicose e Água
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| By 11 weeks
the nose and lips
are completely formed.
As with every other body part,
their appearance
will change at each stage
of the human life cycle.
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| The intestine starts
to absorb glucose and water
swallowed by the fetus.
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| Though sex is determined
at fertilization,
external genitalia can now
be distinguished
as male or female.
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