1. The Pregnancy Project Weeks 1-2 Mrs. Teare First Block

2. Morula 6 hours after Fertilization 1. perivitelline space 2. zona pellucida 3. cell membrane 4. artifacts

3. 36 hours 1. zona pellucida 2. perivitelline space 3. blastomere #1 4. blastomere #2 5. cell membrane of blastomere #1

4. 56 hours 1. zona pellucida 2. perivitelline space 3. polar body

5. 5 days Blastocyst leaves the Zona Pellucida

6. Hatched Blastocyst 1. embryo at the blastocyst stage 2. empty zona pellucida

7. 8-9 days 1. amniotic ectoderm 2. epiblast 3. amniotic cavity 4. hypoblast

8. 11 Days 1. amniotic cavity 2. extra-embryonic endoderm 3. amnion ectoderm 4. epiblast 5. hypoblast 6. primary yolk sac (also called the primary umbilical vesicle)

9. HCG Human Chorionic Gonadotropin  Hormone made by the placenta  Detected about 24 hours after implantation  Blood – detected about 11 days after conception  Urine- detected about 12-14 days after conception  Doubles every 48-72 hours in pregnancy  Often used as a marker to estimate age of gestation.  Can have a normal pregnancy with very low levels of HCG

10. Corpus Luteum  The follicle from which the fertilized egg was released.  Produces progesterone to support the pregnancy until the placenta is able to take over at around 10 weeks.  Low levels of progesterone can cause loss of the pregnancy.  Sometimes needs to be supplemented during the first trimester if maternal levels are low.  Progesterone inhibits immune responses, decreases prostaglandins, and prevents the onset of uterine contractions (spontaneous abortion).