B0003308 6 day old human embryo implanting - coloured
Credit: Yorgos Nikas. Wellcome Images
6 day old human embryo beginning to implant into
the lining of the uterus (endometrium). As implantation progresses, the inner cell mass begins to form into the bilaminar disc. The two layers are called the epiblast and the hypoblast. An embryo that has been in culture for up to 14 days will remain at this stage of development. Such cultured embryos remain alive but do not progress as they would in the womb.
Scanning electron micrograph
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