Embryo Development

Timeline created by krazeeface4
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    Weeks 1 & 2

    After sexual intercoarse, a sperm cell must swim itself to the fillopian tubes and break through the outer membrane of an egg cell. The chromosomes and other genetic material combines
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    Weeks 3 & 4

    The fertilized egg makes its way to the uterise section and implants itself into the uterine wall. The blastocyt starts dividing and arranging itself into three pancake-shaped layers. The cells begin to realize what part of the body they will be and the three pancake-shaped layers are separeating themselves into certain parts of the body they will become
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    Weeks 5 & 6

    The layers fold over like an omlet and the nervous system begins to take shape. Arms, legs, the jaw, tongue, vocal chords, and heart begin to show signs of development
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    Weeks 7 & 8

    Eyelids, a tailbone (which willl disappear in a few weeks), and other organs that begin to run into the umbilical chord begin to form. The fingers are becoming longer. It has knees and the feet may be long enough to touch each other. The nerves in the brain are beginnning to stretch out
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    Weeks 9 & 10

    The baby has earlobes. Its fingertips are slightly larger than normal because fingerpads are forming, and it can move all of its limbs. The fingers have separated and fingernails are growing. The liver is producing blood, so the yolk sac begins to disappear. The forhead bulges and the brain sits high on the head.
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    Weeks 11 & 12

    Bone begins to harden and teeth form under the gums. The skin is still transparent, and the hads can open and close. The ears are closer to the final positions, the eyelids are less transparent and become closer together, and the intestines are being put into place
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    Weeks 13 & 14

    The fingerprints form, the head is more proportional, and the urinary tract is functioning. The arms are going into proportion, the face is starting to make movements, and a fine layer of hair is forming all over the body
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    Weeks 15 & 16

    The legs are longer than the arms and all limbs are movable. The eyelids are still fused shut, but the baby can sense light. The baby is breathing in the amniotic fluid and is making the lungs stronger. The scalp pattern is developing, toenails are growing, and the baby is pumping around 25 quarts of blood a day
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    Weeks 17 & 18

    The unbilical chord is becoming thicker, the hard cartilage in bones is becoming harder into soft bone, and the hearing is developing. You can see the blood vessels through te skin, the ears are in position and are standing out from the head, and the baby practices its limbs
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    Weeks 19 & 20

    The arms and legs are fully proportional. the brain is deciding the sensory details. Hair is growing slightly on the scalp. Sloughed cells are forming in the bowel and will show up in the first dirty diaper. The skin is covered in a white layer called vernix caseose that protects the skin in the fluid of the uterus
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    Weeks 21 & 22

    the eyebrows and eyelids are fully developed, and the lips are becoming more ditinct while the eye forms behind it (everything except the irises, which still lack pigment). The lips are becoming more distinct and tooth buds are forming under the gums. The skin looks wrinkled until shes old enough to fill it out
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    Weeks 23 & 24

    Loud noises that the baby hears will not effect it after birth. The skin is red and wrinkly, no matter what pigment the skin will be after birth. The taste buds are developing with the repritory tree
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    Weeks 25 & 26

    The baby has recognizable hair color and texture, both of which might change after birth. It starts to grow baby fat that fills out the skin, and itll start to look like a newborn
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    Weeks 26 & 27

    The response to sounds is growing more consistent. The genitals of it, if it's a boy, will start to grow. The eys can open and close, and sleeps at regualr intervals. It can get hiccups, and may suck its fingers.
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    Weeks 28 & 29

    It has eyelashes and will turn its head toward light. Layers of fat are beginning to form and becoming ready for birth. the head id growing bigger to fit the brain, which is forming more neutrons. the skeleton is becoming harder every day and gets about 200 milligrams of calcuim.
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    Weeks 30 & 31

    the baby can distinguish between certain objects, and can tell light and dark. The legs, arms, and torso are filling out due to more body fat forming
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    Weeks 32 & 33

    Some babies will have a full head of hair at this point, but others will have just peach fuzz. The fingernails and toenails have grown in. The skull is pliable, which will help during birth. the skin has become less wrinkled and red.
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    Weeks 34 & 35

    99% of babies can live outside the womb due to lung development. The layers of body fat are filling out more. The amnionic fluid is going away, and the baby puts on an ounce of weight a day
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    Weeks 36 & 37

    The head is dropping lower into the pelvis. The downy hair is shedding and will come out with the first bowel movement. The hair on the head is either very long or just peach fuzz, but either way the hair is fully grown
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    Weeks 38 & 39

    if the baby is born with brown eyes, they might stay that way. if its born dark gray or blue, they might change to brown hazel or green within the first year. the baby has a firm grasp. The fat is still developing. The skin is sloughing off and forming in cycles.
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    Weeks 40 & 41

    The skull bones are separated so they can compress in the birth canal during birth. The toenails and fingernails are ready to begin life growing in the real world. The skin might have started to peel due to it sitting in the amiotic fluid