Human Development

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Human Development

• By Ryan Bumphrey Drew Smith

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Stages of the Embryo

• The Visible Embryo is a visual guide through
  fetal development from fertilization through
  pregnancy to birth.

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Stages of Embryo Cont

• As the human embryo develops, it slowly unfolds
  itself in a pattern similar to the way the golden
  spiral unfolds itself as it spins farther and
  farther away from its center. This is also known
  as the Logarithmic Spiral.

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First Week

• During this period the ovum is in the uterine
  tube. Having been fertilized in the upper part of
  the tube, it slowly passes down, undergoing
  segmentation, and reaches the uterus.

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Second Week

• By the end of this week the ovum has increased in
  size, and the majority of its villi are formed.
  Also the embryo has assumed its true form.

6
Fourth Week

• The embryo is markedly curved on itself, and when
  viewed in profile is almost circular in outline.

7
Fifth Week

• The embryo is less curved and the head is
  relatively of large size. Differentiation of the
  limbs into their segments occurs.

8
Eighth Week

• The shape of the head is gradually reduced and
  the neck is somewhat getting bigger. The upper
  lip is completed and the nose is more formed.

9
Third Month

• The head is extended and the neck is lengthened.
  The eyelids meet and fuse, remaining closed until
  the end of the sixth month. The limbs are
  well-developed and nails appear on the digits.

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Sixth Month

• The body is covered in fine hairs. The skin is
  developed and the border of the nail projects
  from the center of the dermis. Measured from head
  to heels, the total length of the fetus at the
  end of this month is from 30 to 32 cm. long.

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Ninth Month

• The umbilicus is almost in the middle of the body
  and the testes are in the scrotum. At full time
  the fetus weighs from six and one-half to eight
  pounds, and measures from head to heels about 50
  cm. long.

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New Borns

• A new born usually weighs up to an average of 7
  to 9 pounds.

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Children at the age of 8-9
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Children the age of 11-12
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Sources of Info.

• http//www.bartleby.com/107/15.html
• http//www.geocities.com/jyce3/spiral.htm
• http//www.visembryo.com/baby/26_weeks.html