Prenatal
Development
October 7, 2011
Good Morning! 3/6/14
 Today’s
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Interims – Clarity issue
 Next
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Agenda:
week:
Prenatal development
Vocabulary
 Amniotic
Fluid – protects the developing
baby, cushions against bumps or falls
 Conception – when the ovum and a
sperm unite
 Embryo – 2nd stage of pregnancy: 3rd-8th
week. Rapid growth.
 Fetus – 3rd stage: 9th week to birth
Vocabulary
 Ovum
– a female cell or egg
 Placenta – Tissue rich in blood vessels.
Provides path to nutrition.
 Umbilical cord – brings nourishment to the
baby and takes waste away. Stiff and
firm like a garden hose, filled with water.
 Uterus – organ in a woman’s body where
the baby develops.
Conception
 Woman’s
body releases an ovum that
travels through the fallopian tubes to the
uterus.
 Meets up with a sperm and is fertilized.
 Pregnancy begins!
3 Stages of Pregnancy
 Period
of the Zygote – Lasts for 2 weeks
 Period of the Embryo – 3rd-8th week
 Period of the Fetus – 9th week to Birth
Period of the Zygote
 The
zygote (fertilized egg) travels down
fallopian tubes and attaches to uterus
 Uterus provides soft, warm bed and a
source of nourishment
 Zygote grows by cell division – from 1 to a
mass of cells
 At end of this period, zygote is the size of
a pinhead
Period of the Embryo
 2nd
Stage of pregnancy – 3rd-8th week
 Embryo grows rapidly and goes through
lots of important changes
 Mass of cells develop into major systems –
heart, lungs, bones and muscle
 A sac filled with fluid forms around the
embryo for protection
Period of the Embryo
 Sac
is filled with amniotic fluid – cushions
baby against bumps and falls
 The Placenta develops – blood vessels
carry food and oxygen to the placenta
 Umbilical cord brings food and oxygen to
baby and takes waste away
 What would happen if the cord were
pinched?
Period of the Fetus
 3rd
stage – 9th week until birth
 As the baby grows, the fluid around baby
and the uterus expand also
 Body is developing so it can live
independent of the mother
 Fetus gains weight rapidly – from thin and
wrinkly to smooth and rounder
Fetus
 Can
do many things before birth – suck its
thumb, cough, sneeze, yawn, kick, hiccup
and cry.
 Can live outside of the uterus by the 7th
month, but only with lots of medical help
 Premature baby – delayed development
Group Activity
 Write
the following titles on each piece of
paper:
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Period of the Zygote
Period of the Embryo
Period of the Fetus
 Each
person writes one fact until each
has written on each paper and you have
run out of facts
Preparing for birth
 During
the 9th month, baby shifts
downward – dropped into the birth canal
 This shift is called “lightening” – could take
place several days or weeks before labor
begins
 Fetus is typically upside down at this point
– easiest and safest position for birth
 Fetus is less active – less room to move
Preparation
 Mothers
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skin and muscles are stretched
Uterus and abdomen can be stretched up
to 60 times their original size
Return to close to normal size within 6 weeks
or so after birth
 After
born
37-42 weeks, the baby is ready to be