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Day 1: Fertilization
Fertilization occurs when the nucleus of both a sperm and an egg fuse to form a diploid cell, known as zygote. The successful fusion of gametes forms a new organism. -
day 8: Implantation
During this process, a developing embryo, moving as a blastocyst through a uterus, makes contact with the uterine wall and remains attached to it until birth. -
day 16: gastrulation
Gastrulation rearranges the cells of the blastula and ultimately forms the three germ layers of the embryo. The primary layers that will form all of the major body and organ systems of the organism, these germ layers include the ectoderm, mesoderm, and endoderm. -
day 23: heart begins to beat
first functioning embryonic organ formed -
day 32: embryo changes
The embryo is growing even more and its features grow to a bud that after a couple weeks will grow and expand.
Body: heart, liver, umbilical cord, mesonephric ridge
Limb: upper and lower limb buds -
day 44: Embryo changes more
The embryo has grown even more to the point its feautures are starting to become distinctive. For example you can Identify: pigmented eye, eyelid, heart, digital rays, liver prominance, thigh, ankle, foot plate,and the umbilical cord.
Limb: upper and lower limb buds, foot plate, wrist, hand plate with digital rays -
Day 54: Embryo changes more
The baby is growing more and more with the addition and specific senses, primarily they can now can smell and hear.
Head: nose, eye, external acoustic meatus
Body: straightening of trunk, heart, liver, umbilical cord
Limb: upper limbs longer and bent at elbow, foot plate with webbed digits, wrist, hand plate with separated digits
