A Reproductive Lexicon


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Trophoblasts are a heterogeneous population of cells derived from the trophectoderm (the outer cell layer of the blastocyst) that mediate and contribute to the construction of the connection between the mother and fetus at the site of implantation (the placenta). There are considerable species differences in terms of trophoblast differentiation. In humans, the differentiated forms are cytotrophoblasts, syncytiotrophoblasts, and extravillous trophoblasts.