Conception
The start of pregnancy when a male germ cell fertilizes the female germ cell
3 Steps of Fertilization
Capacitation
When sperm are acted upon by female secretions in order to:
ZP3 Receptors
Receptors find in zona pellucida of ovum that sperm cell head proteins bind to
2 Enzymes for Fertilization
Polyspermy
Fertilization of an egg by multiple sperm
2 Steps of Polyspermy Prevention
2. Release of chemicals that deactivate ZP3 receptors
Monozygotic Twins, Triplets…
=Identical clones, result of separation of developing embryonic cells
-Usually occurs 8 days post-fertilization
Dizygotic Twins, Trizygotic Triplets
Representations of 2 or 3 separate syngamy events respectively
Cleavage
=Rapid mitotic divisions of the zygote, resulting in increased numbers of progressively smaller “blastomeres”
Human Embryo
Organism from fertilization to end of 8th week in utero
Implantation
=Attachment of the blastocyst to the lining of the uterus followed by its burrowing into stratum functionalis
Human Fetus
Unborn child from 9th week to delivery
Gestation
Period of intra-uterine development
Parturition
Childbirth
6 Stages of Embryonic Development
*First 3 happen within weeks 1-8
Morula
2 Parts of the Blastocyst
4 Examples of Multipotent Stem Cells
*All can develop into one or more cell type
Somatic Cell Nuclear Transfer
A type of therapeutic cloning in which the nuclear material from a human somatic cell is used to replace the nuclear material from a human oocyte
2 Types of Somatic Cell Nuclear Transfer
3 Decidual Regions of the Embryo
Ectopic Pregnancy
=”Out of normal place” pregnancy (e.g., uterine tube, ovary, visceral peritoneum, or cervical canal)
Eutopic Pregnancy
=Normal implantation
-Occurs within endometrium