Conception (Fertilization)  Joining of the egg and sperm

 Egg ( ovum)  I released each month from the ovary  23 chromosomes  Sperm  23 chromosomes  When Sperm and egg unite we have what is called the zygote ( human cell)

Fertilization  46 chromosomes = zygote has all the genetic material.

Stage 1: Period of the Zygote  Conception until 2 weeks old.  Zygote travels from fallopian tube to uterus  This is a time of rapid cell division  The zygote is nourished from the cell and secretions in the fallopian tube and uterus.

 Implantation:  Occurs when the zygote attaches to the thickened lining in the uterus.  This lining nourishes the zygote ( therefore no menstruation)

Stage 2: Period of the Embyro:  2 weeks to about 8 weeks  During this stage all organs and systems of the baby are made or developed  3 essential structures are formed  1) Placenta  Carries O2 and food to baby  Carries CO2 and waste to the mother  Stores nutrients ( iron, calcium, protein)  Carries infections, antibodies, nicotine, liquor, and drugs to the baby

 2) Umbilical Cord  Connects embryo to the placenta

 Amniotic Sac  Filled with fluid that acts as a shock absorber for minor bumps and falls of themom, equalizes the pressure and provides nourishment.

Stage 3: Period of the fetus  From weeks or birth  Organs and systems grow and mature  Quickening ( 4 th to 5 th month) mom feels life