Pregnancy, Birth, and Childhood Lesson 2 – Development Before Birth

Ch 19-2 – Development Before Birth DO NOW Get a book. Read pages 490-491.

Development Before Birth What’s happening here?

Development Before Birth

Development Before Birth Implantation when a zygote attaches itself to the wall of the uterus Embryo the name for the zygote after implantation (until 9 weeks)

Development Before Birth So how do you know you are pregnant? Signs of Pregnancy: Offset of the menstrual cycle Nausea Unusual tiredness Frequent urination Change of appetite Breast tenderness ? ? ? ? ? ?

Development Before Birth How is pregnancy diagnosed? A blood or urine sample The hormone HCG is released by the embryo and present in the test

Development Before Birth The protective structures of the embryo

Development Before Birth Amniotic Sac fluid filled sac that surrounds the embryo. acts like a shock absorber Protects the growing fetus Keeps the temperature constant Placenta a structure that forms along the lining of the uterus as the embryo implants; “life support system”. Umbilical Cord the cordlike structure that connects the embryo and the placenta. Fetus the name of the embryo after 2 months.

Stages of Embryonic Development

Stages of Embryonic Development

Stages of Embryonic Development

Development Before Birth Other things to consider about development: How many sperm actually survive the journey to the egg? How long is the umbilical cord (on average)? Is blood ever exchanged between mother and fetus? Since a fetus doesn’t breathe, how could the mother’s smoking habit harm it? What options do people have when they have difficulty getting pregnant?