TY - CHAP M1 - Book, Section TI - Chapter 15. Disorders of Development A1 - Chandrasoma, Parakrama A1 - Taylor, Clive R. PY - 1998 T2 - Concise Pathology, 3e AB - The initial divisions of the fertilized ovum (zygote) create a mass of cells (blastocyst) consisting of an inner cell mass (the embryonic disk) surrounded by an outer layer (the trophoblast). The cells of the trophoblast actively penetrate the endometrium and form the placenta. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/19 UR - accessphysiotherapy.mhmedical.com/content.aspx?aid=185152 ER -