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Related to chorioallantois: chorioallantoic


The highly vascular fetal membrane that consists of the fused chorion and allantois, found adjacent to the eggshell in reptiles and birds and constituting the placenta in most mammals.

cho′ri·o·al′lan·to′ic (-ō-ăl′ən-tō′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Anatomy) the membrane of a fetus that is formed by the merging of the allantois and the chorion
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˌkɔr i oʊ əˈlæn toʊ ɪs, -tɔɪs, ˌkoʊr-)

a vascular membrane surrounding the embryo in birds, reptiles, and certain mammals, formed by the fusion of the walls of the chorion and allantois.
cho`ri•o•al`lan•to′ic (-ˌæl ənˈtoʊ ɪk) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.chorioallantois - the very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois
tissue layer, membrane - a pliable sheet of tissue that covers or lines or connects the organs or cells of animals or plants
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
The large part of intact chorioallantois membranes came out from vulva with rapid forceful frequent uterine contraction, and it was immediately incised using sterile BP blade.
Butler, "Growth and development of the tetracotyle of Cotylurus strigeoides (Trematoda) in the chick, on the chorioallantois and in vitro," Proceedings of the Helminthological Society of Washington, vol.
Histopathology did not reveal any infectious organisms in the fetal tissues; however, the chorioallantois showed moderate villous atrophy, which was presumed to be the cause of fetal death.