Talk:1987 Developmental Stages In Human Embryos - Stage 1
From Embryology
Table 1-1. Tabulaton of the First Three Stages
Stage | Event | Products | ||
---|---|---|---|---|
Meiotic division 1 | Oocyte 2 and polar body 1 | |||
Beginning of meiotic division 1 and ovulation | Ovulated oocyte | |||
1a | Fertilization | Penetration | Penetrated oocyte | |
1b | Fertilization | Completion of meiotioc division 2 and formation of pronuclei | Ootid and polar body 2 | |
1c | Fertilization | Pronuclei enter cleavage division | Zygote | |
2 | Cleavage continues | 2 to about 16 cells | ||
3 | Formation of blastocystic cavity | Blastocyst, from about 32 cells onward |