part of part of develops from develops from amnion extraembryonic structure unilaminar epithelium epiblast (generic) amniotic ectoderm VHOG:0000621 amnionic ectoderm amnion epithelium EMAPA:16110 EHDAA2:0000117 EHDAA:138 UBERON:0003254 UBERON:0008359 amnion ectoderm BTO:0000897 extraembryonic tissue