Prenatal Development October 7, 2011

Good Morning! 3/6/14  Today’s Agenda:  Turn in Portfolio Entry #2  Finish Prenatal Development Video  Start Prenatal development notes  Interims – Clarity issue  Next week:  Prenatal development

Vocabulary  Amniotic Fluid – protects the developing baby, cushions against bumps or falls  Conception – when the ovum and a sperm unite  Embryo – 2 nd stage of pregnancy: 3 rd -8 th week. Rapid growth.  Fetus – 3 rd stage: 9 th 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 – 3 rd -8 th week  Period of the Fetus – 9 th 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  2 nd Stage of pregnancy – 3 rd -8 th 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  3 rd stage – 9 th 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 7 th month, but only with lots of medical help  Premature baby – delayed development

Group Activity  Write the following titles on each piece of paper:  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 9 th 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 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 weeks, the baby is ready to be born