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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.


(Anatomy) the membrane of a fetus that is formed by the merging of the allantois and the chorion


(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.
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
References in periodicals archive ?
Stage II is marked by rupture of chorioallantois and delivery of foetus which often occurs in less than 30 minutes.
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.