Cellular basis of interaction between trophoblast and uterus at implantation.
A COMPARATIVE STUDY OF THE FINE STRUCTURE OF THE TROPHOBLAST IN SEVERAL HEMOCHORIAL PLACENTAS.
- A. Enders
- Biology, MedicineAmerican Journal of Anatomy
All of the placentas show both surface and basal modifications of trophoblast, but caveolae (pinocytotic vesicles) were found to be most commonly located in crypts, pockets, or other regions somewhat removed from the surface.
Comparative aspects of trophoblast development and placentation
It is argued that a definitive epitheliochorial placenta is a secondary specialization and that it evolved twice,once in the Laurasiatheria and once in the lemurs and lorises.
A morphological analysis of the early implantation stages in the rat
By making use of the known sequence of ovulation and fertilization in Holtzman rats, the Pontamine Blue reaction, and electron microscopy, the first stages in implantation were studied, and many of the cytological features observed during the process are described.
Pinocytotic activity of the uterus of the rat.
It is suggested that pinocytosis might play a role in producing apposition of the blastocyst to the luminal epithelium, in passing information from the blastocytes to the stroma, and in diminishing the molecular contents of the uterine lumen during specific times in the reproductive process.
Implantation in the rhesus monkey: initial penetration of endometrium.
It was concluded that syncytial trophoblast is the first tissue to penetrate the uterine luminal epithelium; that invasion is accomplished with less destruction of maternal tissue than previously suggested; and that the rapid superficial growth of the placenta is made possible by the early tapping of the endometrial vessels.
Cytological aspects of trophoblast-uterine interaction in early implantation.
It is suggested that the capacity of trophoblast to form junctions with epithelial cells is an important part of the implantation process, facilitating penetration of the endometrium without dislodgment of the blastocyst.
What can comparative studies of placental structure tell us?--A review.
Differentiation of the embryonic disc, amnion, and yolk sac in the rhesus monkey.
The inner cell mass of the blastocyst has differentiated into epiblast and hypoblast (primitive endoderm) prior to implantation and presumptive mesoderm cells are undifferentiated, whereas extraembryonic mesod Germ cells are already a distinct population forming extracellular materials.