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The Endowment for Human Development
The Endowment for Human Development
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Slideshow: Early Events

Seven-Cell Embryo

#46, Slide 9 of 24

54 hours

Source: Centro Riproduzione Assistita, Catania, Italy.

Note:

As the cells divide and increase in number, the overall size of the embryo remains essentially unchanged. The large blastomere will be the next to divide.

Label Key:

1. zona pellucida
2. perivitelline space
3. large blastomere
All ages referenced to fertilization, not last menstrual period.
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