A patch of endodermal cells (End.) which forms a cap over the end of the secondary umbilical vesicle cavity is seen in the lower part of this figure. There is no definite line of demarcation between the patch of endoderm and the dense tissue which extends to the posterior wall of the amnion. Section 156.
Fig. 11. Heuser et al., 1945.
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Keywords: endoderm, secondary umbilical vesicle cavity
Source: The Virtual Human Embryo.