humandevtin utero

7/28/2019 Humandevtin Utero

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Human Development in utero

Fertilization:

The sperm joins with the ovum (egg) to form one cell -- the zygote.

This one cell contains the complex genetic blueprint for every detail of humandevelopment: the childs sex, hair and eye color, height, skin tone, etc.

First Month

First cell division

This first cell, the zygote, divides within about 10 hours and then cell divisioncontinues in an orderly fashion every few hours as the small group of cells travels

down the Fallopian tube to the uterus, where the uterine lining has been prepared forimplantation.

There are over 100 cells already present when this tiny human embryo (blastocyst)reaches the uterus 7-10 days after fertilization. Upon implantation, complexconnections between the mother and the embryo develop to form the placenta.

Benchmark Dates:

Day 18 blood vessels and the heart begin to form

Day 20 foundations of the brain, spinal cord, and nervous system are alreadyestablished

Day 25 the heart begins to pulsate and will continue until this person dies; thedigestive system and parts of the eyes are forming

Day 28 the backbone and the rest of the skeleton (cartilage now) and muscles areforming; arm and leg buds are present and elongating

Early growth

At one month old, the embryo is 10,000 times larger than the original microscopicfertilized egg, and is developing rapidly. The heart is pumping increased quantities ofblood through the circulatory system.


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The placenta forms a unique barrier that keeps the mothers blood separate whileallowing food and oxygen to pass to the developing human embryo. The word"embryo" is Latin and means "a budding".

Second Month

Day 35 the preborn human embryo now has the 3 main parts of the brain, as wellas eyes, ears, nasal organs, liver, and gall bladder; arm and leg buds are dividing intotheir sections (hand, arm etc.). During this week the heart will divide into 4 chambersand the little human embryo may begin to move.

Day 42 (6 weeks) brainwaves can be detected on the EEG and the EKG can berecorded. The brain is presently controlling 40 sets of muscles as well as all bodyorgans. Fingers, then toes, begin to form.

The embryo is about 1/5 inch long. Mouth, liver, and intestines begin to take shape.The jaw forms, including teeth buds in the gums. The stomach produces digestivejuices and the kidneys have begun to function.

8 Week human embryo

Day 56 (8 weeks) the human embryo is 1.5 inches long and is now referred to asthe "fetus", a Latin word meaning "young one", or "offspring".

The face appears quite human. Hands and feet are distinctively human.

At the end of 8 weeks all organs are present; during the remainder of the pregnancythe organs will mature and become fully operational. For example, the cartilage inthe skeleton now begins to be replaced by bone cells.

Third Month

Day 63 (9 weeks) -The preborn human fetus, the "young one", now sleeps, andexercises her muscles by turning her head, curling her toes, and opening and closingher mouth. The eyelids seal during this time to protect the developing light sensitiveeyes which will reopen Week 25.

She can respond to touch by making a tight fist when her palm is stroked. Shebreathes amniotic fluid while developing her muscles and her whole respiratorysystem; the diaphragm becomes functional this month. As many as one hundred


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hiccups an hour have been counted in the "young one" during these early months,possibly to strengthen the diaphragm.

Day 84 (12 weeks) -All the organs and systems of her body are developed andfunctioning. External genitalia fully differentiate into male or female. Body length hasdoubled since Week 8 to about 3 inches.

The only major activity that will now take place until birth is growth, the increase inher size.

Fourth Month

Week 14

The human fetus is now about 4-5 inches long and weighs almost an ounce. The

muscles begin to develop. Fingernails and toenails develop. The child's spontaneousmovements can be observed.

14 Week Human

By the end of this month, the preborn child is about 6 inches in length and weighsabout 7 ounces. Unique fingerprints are evident and will never change. Her ears arefunctioning, and there is much evidence that she hears her mothers voice andheartbeat, as well as external noises. The umbilical cord has become an engineeringmarvel, transporting 25 quarts of fluid per day and completing a round-trip of fluidsevery 30 seconds. Because the preborn child is now larger, the mother usually beginsto feel her babys movements during this month.

Fifth Month

Half the pregnancy has now passed, and the preborn child is about 6 inches long. Thepreborn fetus exhibits good muscular strength and coordination, kicks, moves, andturns in the womb, hiccoughs, and develops sleep-wake patterns. If a sound isespecially loud or startling, the young one may jump in reaction to it.

Week 18

The fetus is now about 6-8 inches long. The child blinks, grasps, and moves hermouth. Hair grows on the head and body.

By the end of the fifth month, the "young one" will be about 10 inches tall and weighabout a pound. Babies born at this time (19-20 weeks) are surviving at an increasingrate thanks to improving medical technology.


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Sixth Month

21 Week Human Oil and sweat glands are functioning. The delicate skin of the youngone is protected from the waters in the amniotic sac by a special ointment called"vernix".

Week 22 The fetus now weighs approximately 1/2 a pound and spans about 10inches from head to toe. Sweat glands develop, and the external skin has turned fromtransparent to opaque.

By the end of the sixth month, the "young one" weighs about two pounds and may be

up to 12 inches long.

Seventh Month

The preborn human fetus now weighs 2-3 pounds and uses the four senses of vision,hearing, taste, and touch. Research has documented that she can now recognize hermothers voice. About 2 more pounds are added by the end of this month.

Eighth Month

36 Week Human The skin begins to thicken, with a layer of fat stored underneath forinsulation and nourishment.

Fingernails have reached the tips of the fingers. Antibodies increasingly build up.

The "young one" swallows a large amount of amniotic fluid per day; she has beenurinating for several months. The "young one" gains about two more pounds thismonth.


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Ninth Month

During these final weeks, approximately 14 grams of fat are laid down per day. The"neonate" weighs about 7-8 pounds and may be 14-20 inches long.

Toward the end of this month, the preborn child is ready for birth. The averageduration of pregnancy is 280 days, from the first day of the mothers last menstrualperiod; but this varies.

By this time, the preborn childs heart is pumping 300 quarts of blood per day. The"young one" triggers labor and birth occurs. Of the 45 generations of cell divisionsthat will occur in every person, 41 take place in the uterus (womb). Only four morewill occur during the rest of childhood and before adolescence.

Newborn

Scientists know a distinct human life begins at conception (fertilization).

From conception (fertilization) onward, the preborn child is a living, developingindividual with a uniquely human genetic makeup, different from the mothers andfathers genetic codes.

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