Source:http://linkedlifedata.com/resource/umls/id/C0005712
MSH: Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.,NCI: The undifferentiated cells formed by cleavage of the fertilized ovum. This includes cells in the cleavage, morula, and blastula stages of the embryo. (MeSH)