Definition of Chorion
Chorion: The outermost of the two fetal membranes (the amnion is the innermost) that surround the embryo. The chorion develops villi (vascular finger-like projections) and develops into the placenta.
Source: MedTerms™ Medical Dictionaryhttp://www.medterms.com/script/main/art.asp?articlekey=2719
Last Editorial Review: 3/19/2012
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