Syncytiotrophoblast (from the
Greek 'syn'- "together"; 'cytio'- "of cells"; 'tropho'- "nutrition"; 'blast'- "bud") is the
epithelial covering of the highly vascular
embryonic placental villi, which invades the wall of the
uterus to establish nutrient circulation between the embryo and the mother. It is a unique tissue in that it is a multi-nucleated, terminally differentiated
syncytium, extending to 13cm .