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Carnegie Stage   Figure

Section through middle of specimen

Section through middle of specimen

Section through the middle of the embryo. The space outlined by the internal surface of the chorion now appears distended again. However, a gradient of differentiating trophoblast from abembryonic to embryonic pole is still evident. Intercommunicating lacunae are visible in the syncytiotrophoblast. The primary umbilical vesicle, surrounded by a meshwork, can be seen. The endometrial stroma is edematous and decidua is developing.

Fig. 13. O'Rahilly and Müller, 1987

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Keywords: abembryonic pole, chorion, embryonic pole, endometrial stroma, intercommunicating lacunae, primary umbilical vesicle, syncytiotrophoblast, trophoblast


Source: The Virtual Human Embryo.