From Egg to Embryo
•Accomplishing fertilization
§Sperm transport & capacitation
§Acrosomal reaction & sperm penetration
§Blocks to polyspermy
•Pre-embryonic development
§Cleavage & blastocyst formation
§Implantation
§Placentation
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1.Egg lives 12-24 hours after ovulation, sperm lives up to 3 days.
2.Fertilization
1.Sperm goes through vagina, cervix. Must be capacitated-membrane must be fragile enough to allow enzymes in acrosomes to be released.
2.Release of enzymes and entry into the egg.
3.Fast-block- forms barrier to other sperm form entering egg.
3.Development
1.Cleavage-period of fairly rapid mitotic divisions of the zygote during fertilization. Blastocyst is a fluid-filled hollow sphere composed of a single layer of large, flattened cells.
2.Attachment of blastocyst to uterine wall
3.Formation of the placenta