part_of part of composed primarily of syncytiotrophoblast cell syncytiotrophoblast UBERON:0000371 EHDAA:129 NCIT:C33918 EHDAA:91 syncytial trophoblast FMA:83040 Extraembryonic cells of trophoblastic shell surrounding embryo, outside the cytotrophoblast layer, involved with implantation of the blastocyst by eroding extracellular matrix surrounding maternal endometrial cells at site of implantation, also contribute to villi. (dark staining, multinucleated). EMAPA:16068 BTO:0001335 syntrophoblast Wikipedia:Syncytiotrophoblast syntrophoblast layer uberon SCTID:256965005 syncitiotrophoblast embryonic structure ectoplacental cone