• Fertilized egg

    Allan's egg is fertilized
  • 2 Cell stage

  • 4 cell stage

  • 8 cell stage

  • Compacted 8 cell

  • Morula

  • Blastocyst

  • ICM Growth

  • Blaminar Germ disk

  • Amniotic Cavity/yolk sac

    week 3 marker
  • Implantation complete

  • Extraembryonic mesoderm

  • Hypoblast cells replaced

  • Mesoderm Immigraion

    Week 4 marker
  • Ectoderm formation

  • Primariy neurulation

  • Secondary neurulation

  • neurulation complete

  • Embryonic folding

    Week 5 marker
  • Primitive gut tube forms

  • Major Blood vessels form

  • Upper limb bud forms

    week 6 marker
  • Lower limb bud forms

  • hand plate forms

    week 7 marker
  • Webbed fingers and toes

    week 8 marker
  • Fingers/toes separate

    week 9 marker
  • Gonads differentiate by sex

  • eyelids form

  • gonads differentiate by sex

    week 10 marker
  • eyelids form

    week 12 marker
  • iris develops

    week 14 marker
  • second trimester

    week 15 marker
  • Taste pores develop

    week 16 marker
  • fetus weighs about 100g

    week 18
  • vernix caseosa covers skin

    week 19 marker
  • larnugo replaced by vellus

    week 20
  • fetus weighs 500g

    week 23 marker
  • hpa axis established

    week 22 marker
  • 50% survival if born

    week 24 though 42 begins
  • Allan Jr. is born

    week 42