["Ultrastructural aspects of amniotic-fluid cells". A. Non-vital cells. I. Periderm-cells (author's transl)].
The surface layer of fetal epidermis in early pregnancy, the Periderm, is progressingly replaced by the final keratinization process during fifth to sixth month of gestation. Then the peridermal cells are shed into the amniotic fluid. It is still controversial, whether complete peridermal cells or just their globular protrusions are separated. Formation of mikrovilli and invaginations of plasma membrane, the numerous smaller and larger vacuoles and the cytoplasmatic meshwork of fine filaments without production of keratohyaline, are characteristics of peridermal cells, and are described in detail by electron microscopical investigations on cells suspended in the amniotic fluid, which are most likely of peridermal origin.
D000653:Amniotic Fluid / Q000166:cytology* / Q000648:ultrastructure; D002462:Cell Membrane; D004721:Endoplasmic Reticulum; D005260:Female; D006801:Humans; D011247:Pregnancy; D014617:Vacuoles
"Zur Feinmorphologie der Fruchtwasserzellen". A. nichtvitale Zellen. Teil 1: Periderm-Zellen.