Quick Vocabulary
Chorion
Develops a rich supply of blood vessels and forms an intimate
association with the endometrium (lining) of the female’s uterus.
Chorion and endometrium together form the placenta
Amniotic
sac
A membrane sac begins to fill with fluid. It is the inner membrane of the
chorion.
Amniotic
fluid
A pale yellow fluid that serves to cushion the unborn baby from jolts and
bumps. It provides a stable temperature and assists in maintaining a
consistent body temperature. The fluid allows the baby to move freely
and exercise growing muscles to develop a symmetrical musculoskeletal
system. It allows for lung development as the baby begins to breathe
amniotic fluid to strengthen his lungs and swallow fluid to develop the
gastrointestinal tract. The kidneys develop as the baby urinates in the
fluid.
Umbilical
cord
Nutrients and oxygen move from the mother’s blood into the placenta,
through the umbilical cord, and then to the fetus. Wastes are the fetus
move through the umbilical cord, to the placenta, and then into the
mother’s blood
LEFT
Think, Pair, Write:
What do you
notice?
Write about the
placenta, the
chorion and the
amniotic sac
Do identical twins always share a
placenta during pregnancy?
No, this is a myth. Even many doctors will
mistakenly identify twins as fraternal because
there are two placentas. It depends on when
the egg splits. If it is early enough, the two
embryos will implant separately in the uterus
and develop individual placentas. If the split
occurs later, they may share a placenta.
LEFT
Use your book, pg 518 – 520:
Create two lists:
Think, Pair, Write:
What do you notice?
Write about the umbilical cord.
1) Important things for fetal
growth
2) Things that are bad for fetal
growth
The placenta
contains many blood
vessels from both
the fetus and the
mother, but they are
NOT directly
connected.
Quick quiz – what do all these mean?
LEFT
Stomach vs. Uterus
Think, Pair, Write:
What do you
notice?
Write about the
differences in
location and
function of the
stomach and the
uterus.
• http://kids.britannica.com/comptons/art90799/Identical-twins-left-and-fraternal-twinsright-both-get-nourishment
• http://www.smh.com.au/news/health/doubletrouble-this-pair-could-hardly-comecloser/2006/02/17/1140151818765.html
• http://www.biog11051106.org/demos/105/unit8/ovaryplacenta.html
• http://stages-of-pregnancydevelopment.com/pregnancy-week-13/