conceptus n : an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life [syn: embryo, fertilized egg]
EtymologyDerived from the Latin concipere
Conceptus (latin is conceptio, derivatives of zygote) denotes the embryo and its adnexa (appendages or adjunct parts) or associated membranes (i.e. the products of conception) The conceptus includes all structures that develop from the zygote, both embryonic and extraembryonic. It includes the embryo as well as the embryonic part of the placenta and its associated membranes - amnion, chorionic (gestational sac), and yolk sac.