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

Six-Cell Embryo

#45, Slide 8 of 24

52 hours

Source: Centro Riproduzione Assistita, Catania, Italy.

Note:

The three-dimensional nature of the developing embryo becomes more evident with each cell division.

Label Key:

1. perivitelline space
2. zona pellucida
3. blastomere "in the middle"
All ages referenced to fertilization, not last menstrual period.
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