I would like to thank Dr. Frederick Kraus, Associate Pathologist, St. Luke's Hospital, and the Department of Obstetrics and Gynecology, Washington University School of Medicine, especially Dr. Ernst Friedrich, for aid in getting the early placental stages. This work was supported by grants GB-5024 from the National Science Foundation, and 1 RO1 HD 02613 from the National Institute of Child Health and Human Development.
Fine structure of anchoring villi of the human placenta†
Article first published online: 3 FEB 2005
Copyright © 1968 Wiley-Liss, Inc.
American Journal of Anatomy
Volume 122, Issue 3, pages 419–451, May 1968
How to Cite
Enders, A. C. (1968), Fine structure of anchoring villi of the human placenta. Am. J. Anat., 122: 419–451. doi: 10.1002/aja.1001220302
- Issue published online: 3 FEB 2005
- Article first published online: 3 FEB 2005
Anchoring villi from the first trimester, early second trimester, and term were examined with the electron microscope. It was found that the small anchoring villi of the third and fourth month were particularly informative, since at this stage the cytotrophoblast is still proliferating, yet these cells form a compact discoidal region at the surface of the basal plate. Transitions from relatively undifferentiated cytotrophoblast cells adjacent to the stroma of the villus to large isolated cells surrounded by fibrinoid could readily be followed. These highly differentiated cytotrophoblast cells were found to have extensive regions of fine filaments, in addition to their pronounced endoplasmic reticulum, and were designated fibrous cytotrophoblast cells. The nature of the frequently incomplete epithelium covering anchoring villi at term was described, and some of the functions of the cytotrophoblast are discussed in relation to the observations of their fine structure.