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Chorion
Outermost fetal membrane around the embryo in amniotes / From Wikipedia, the free encyclopedia
For the entertainment company, see Chorion (company).
The chorion is the outermost fetal membrane around the embryo in mammals, birds and reptiles (amniotes). It develops from an outer fold on the surface of the yolk sac, which lies outside the zona pellucida (in mammals), known as the vitelline membrane in other animals. In insects, it is developed by the follicle cells while the egg is in the ovary.[1] Some mollusks also have chorions as part of their eggs. For example, fragile octopus eggs have only a chorion as their envelope.[2]
Quick Facts Details, Identifiers ...
Chorion | |
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![]() Diagram showing the chorion of a chicken egg | |
![]() Human fetus enclosed in the amnion | |
Details | |
Identifiers | |
Latin | chorion |
MeSH | D002823 |
TE | E5.11.3.1.1.0.3 |
Anatomical terminology |
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