17 Embryology (Pre-Embryonic Phase) Flashcards
1
Q
What are the key events of the pre-embryonic phase?
A
Fertilization
Cleavage
Blastocyst formation
2
Q
What is the timeline of the pre-embryonic phase
A
from fertilization to the end of week 1
3
Q
what occurs in fertilization?
A
a zygote is formed by the fusion of two gametes (egg and sperm), usually in the ampullary region of the uterine tube
4
Q
what occurs in cleavage?
A
rapid mitotic divisions occur in the newly formed zygote. each identical daughter cell is called a blastomere, and the cluster of blastomeres is called a morula
5
Q
what occurs in blastocyst formation?
A
the morula differentiates into two layers, forming a blastocyst
the inner layer (embryoblast) will form the contents of the embryo
the outer layer (trophoblast) will form the extraembryonic tissues
