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Day 1 - Fertilization
The fusion of between egg and the sperm occurs, forming a zygote. -
Day 4 - Hatching
The blastocyst hatches out of the protective zona pellucida. The hatching allows an increase in growth, access to uterine nutrient selections, and blastocyst adhesion to the uterine lining. -
Day 7/8 - Implantation
The embryo adheres to the wall of the uterus. By this adhesion, the embryo receives oxygen and nutrients from the mother. -
Day 23 - Heart
The heart starts to beat during day 23. -
Day 29 - Respiratory System
The left and the right lung buds start to push into the pericardioperitoneal canals (primordia of the pleural cavity). -
Day 35/37 - Vision
The retinal pigmentation in the eyes starts to form. -
Day 42 - Heart
The heart separation of cardiac outflow occurs. The aortic arch and the pulmonary aorta forms. -
Day 56 - Extraembryonic Coelom
The chorionic cavity is now lost by fusion with the expanding amniotic cavity.
