| ectoplacental | 1. Outside, beyond, or surrounding the placenta; in primates, referring especially to the parts of the trophoblast not directly involved in the formation of the placenta. 2. In rodents, referring to the actively growing part of the trophoblast involved in the formation of the placenta. (05 Mar 2000) |
|---|---|
| ectoplacental cavity | A developmental cavity that exists in some mammals and is derived by division of the proamniotic space; it is further removed from the embryo than the amniotic cavity in some mammals. Synonym: ectoplacental cavity. (05 Mar 2000) |