Cells lining the outside of the BLASTOCYST. After binding to the ENDOMETRIUM, trophoblasts develop into two distinct layers, an inner layer of mononuclear cytotrophoblasts and an outer layer of continuous multinuclear cytoplasm, the syncytiotrophoblasts, which form the early fetal-maternal interface (PLACENTA).
Cells lining the outside of the BLASTOCYST. After binding to the ENDOMETRIUM, trophoblasts develop into two distinct layers, an inner layer of mononuclear cytotrophoblasts and an outer layer of continuous multinuclear cytoplasm, the syncytiotrophoblasts, which form the early fetal-maternal interface (PLACENTA).
Trophoblasts with single nucleus and defined cellular structures. As the PLACENTA develops, pockets of cytotrophoblasts serve as stem cells for syncytiotrophoblasts.
Trophoblasts with multinuclear cytoplasm and undefined cellular structures. Syncytiotrophoblasts secrete proteolytic enzymes that erode the ENDOMETRIUM for EMBRYO IMPLANTATION. They also produce steroid, peptide, and protein hormones (PLACENTAL HORMONES).
