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Day 1
CONCEPTION!!! An egg is fertilized by a sperm -
Day 7
Blastocyst - a hollow ball of cells; embryo implants in the uterus -- YAY -
Day 21
There are 3 cell layers - endoderm, mesodern, and ectoderm. The basic body plan is determined, and the placenta begins to function -
Week 4-8
The nervous system develops (prmitive heart and neural tube are formed). Major body systems form but are not developed yet. Major organs develop. Arm and leg buds form; the heart pumps blood for the first time. The fetus has its own blood time. Face, head, and eyes develops. By week 8, FETUS!!! Brain grows rapidly and ears take shape. -
Week 10
Genitals form but the sex cannot be determined. Eyelids close until the 7th month and the heart is almost completely developed. -
Week 12
Vital organs begin to function, fingernails develop, and the face has a human profile. -
Week 14
Baby's neck has become defined, the arms have lengthened, the facial muscles are working, the lanugo is developed, red blood cells are formed in the spleen, and the sex can be determined. The baby weighs about 1 1/2 ounces and is about 3 inches long -
Week 15
Skeleton is developing, scalp hair pattern is forming, light can be sensed, and are breathing the amniotic fluid. All joints and limbs can be moved. -
Week 16
6 1/2- 7 inches long, weighs 6-7 ounces, develops reflexes such as sucking and swallowing, tooth buds are developing, sweat glands form, fingers and toes are defined, skin is bright pink because the circulatory system is working, toenails form -
Week 17
Fat stores begin to develop, sense of hearing is developing, skeleton is turning into hardened bone -
Week 18
Baby can hear, more movement, ears are fully in position -
Week 19
Vernix casiosa begins to cover the baby which protects the baby's skin, specialized areas in the brain are developing, legs are now proportionate, hair begins to grow on baby's head -
Week 20
Meconium is accumulating in the baby's bowel -
Month 6
Baby can suck its fingers and can get hiccups, head grows bigger and the skeleton hardens -
Month 7
Can open and close eyelids, can distinguish between light and dark, wakes and falls asleep, baby's skull is stil plyable, baby's lungs are well developed -
Month 9
The amniotic sac ruptures, the skull bones are separated, the baby's skill peels off, then BOOM, baby is born
