1Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas USA. 2Heart Research Center, Portland, Oregon, USA.
The International Journal of Developmental Biology is well known for its outstanding Special Issues on systems, processes and organs. In this Special Issue, the placenta is the topic of discussion for the first time. In women, this unique organ develops and declines within the nine months of pregnancy. One portion of the placenta, the trophectoderm, is the first identifiable layer of differentiated cells in the blastocyst. The trophectoderm and its descendents, the trophoblast cells, overlie mesenchyme, a mixture of cell types supplied by the inner cell mass. The mesenchyme is contiguous with the fetal umbilical cord that is attached to the fetal abdominal cavity....
Placenta, Allen C. Enders, Special Issue, Int. J. Dev. Biol., Preface