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the outermost extraembryonic membrane [ MESH:A10.615.284.473 MP:0002836 ]

Synonyms: embryonic chorion chorion uterine chorion fetal chorion chorion (vertebrates)

This is just here as a test because I lose it

Term information

database cross reference

uberon_slim, efo_slim, pheno_slim

depicted by


development notes

Extra-embryonic ectoderm

external definition

The outer membrane of the two membranes enclosing the embryo in reptiles, birds, and mammals. In placental mammals it contributes to the development of the placenta[BTO:0000252].

The outer membrane enclosing the embryo in reptiles, birds, and mammals. [TFD][VHOG]

has related synonym

chorionic sac

chorion frondosum

homology notes

Structures homologous to the four extraembryonic membranes of reptiles and birds appear in mammals: amnion, chorion, yolk sac, and allantois.[well established][VHOG]



taxon notes

The chorion of placentals is bilaminar as in reptiles and birds, but forms from the trophoblast and includes the ajdacent mesodermal layer [ISBN:0073040584]