• http://www.youtube.com/watch?v=pVII-lCAUE
Baby’s Support System
Aims
• All will be able to name the main parts of the
baby’s support system
• Some will understand the function of at least
two areas of the baby’s support system
• A few will be able to describe the functions of
the placenta and amniotic sac in detail.
What supports the baby in the
womb?
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Umbilical cord
Mother’s cervix
Amniotic sac
Amniotic fluid
Uterus
Placenta
http://www.5min.com/Video/What-is-APlacenta-96171296
Placenta – is attached to the wall of
the uterus and the other side of the
baby via the umbilical cord. It
develops from the chorion
In the third stage of labour the
placenta (afterbirth) is delivered.
Functions of the placenta :• transfers oxygen from the mother
to the foetus and removes carbon
dioxide and waste products from
the foetus’s blood.
•It carries nutrients
•It passes antibodies
•Allows the foetus to eat, breathe
and dispose of waste.
•Produces hormones that maintain
pregnancy.
Amniotic sac and fluid
Inside the uterus there is a sac
(amniotic sac). The main purpose of
the sac is to ensure the foetus grows
safely.
The main functions of the fluid are;•Allows the foetus to float freely in
the early stages.
•Keeps the foetus at a constant warm
body temperature.
•Supports, cushions and protects the
foetus from knocks, falls and bangs.
• The uterus is a strong muscle that keeps the baby secure
and protected. It expands in size. During labour the
uterus contracts to push the baby out.
• The umbilical cord is the baby’s lifeline. It connects the
baby to the placenta, and it carries blood and nutrients
to the baby and removes waste products.
• The cervix and cervical mucus – The cervix is the neck of
the womb. During pregnancy it is blocked with a mucus
plug. This protects the uterus from infections.
Key words
Chorion = the outer layers of cells that develops from a
fertilised egg.
Chorionic villi = blood vessels where nutrients/waste are
exchanged from the mother’s and baby’s blood.
What is the difference between an
embryo and a foetus?
At conception a ZYGOT is formed which is a tiny bundle
of cells. This keeps growing until implantation.
EMBRYO: From implantation until 8 weeks the
developing baby is called an embryo.
FOETUS: At 8 weeks the developing baby has
everything that it will need when it is born and is
now called a foetus.
Design a fact sheet that explains the baby’s support
system.
Remember this includes the placenta, amniotic sac and
fluid, cervix, umbilical cord and uterus.
The idea is that a fact sheet is to provide information in
a clear and precise way. It gives the ‘facts’ and does
not contain pointless information!