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Multilingual Illustrated DVD [Tutorial]
The Biology of Prenatal Development
Table of Contents
- THE EMBRYONIC PERIOD (THE FIRST 8 WEEKS)
- EMBRYONIC DEVELOPMENT: THE FIRST 4 WEEKS
- Chapter 3 – Fertilization
- Chapter 4 – DNA, Cell Division, and Early Pregnancy Factor (EPF)
- Chapter 5 – Early Stages (Morula and Blastocyst) and Stem Cells
- Chapter 6 – 1 to 1 1/2 Weeks: Implantation and Human Chorionic Gonadotropin (hCG)
- Chapter 7 – The Placenta and Umbilical Cord
- Chapter 8 – Nutrition and Protection
- Chapter 9 – 2 to 4 Weeks: Germ Layers and Organ Formation
- Chapter 10 – 3 to 4 Weeks: The Folding of the Embryo
- EMBRYONIC DEVELOPMENT: 4 TO 6 WEEKS
- Chapter 11 – 4 Weeks: Amniotic Fluid
- Chapter 12 – The Heart in Action
- Chapter 13 – Brain Growth
- Chapter 14 – Limb Buds and Skin
- Chapter 15 – 5 Weeks: Cerebral Hemispheres
- Chapter 16 – Major Airways
- Chapter 17 – Liver and Kidneys
- Chapter 18 – Yolk Sac and Germ Cells
- Chapter 19 – Hand Plates and Cartilage
- EMBRYONIC DEVELOPMENT: 6 TO 8 WEEKS
- Chapter 20 – 6 Weeks: Motion and Sensation
- Chapter 21 – The External Ear and Blood Cell Formation
- Chapter 22 – The Diaphragm and Intestines
- Chapter 23 – Hand Plates and Brainwaves
- Chapter 24 – Nipple Formation
- Chapter 25 – Limb Development
- Chapter 26 – 7 Weeks: Hiccups and Startle Response
- Chapter 27 – The Maturing Heart
- Chapter 28 – Ovaries and Eyes
- Chapter 29 – Fingers and Toes
- THE 8-WEEK EMBRYO
- THE FETAL PERIOD (8 WEEKS THROUGH BIRTH)
- Chapter 37 – 9 Weeks: Swallows, Sighs, and Stretches
- Chapter 38 – 10 Weeks: Rolls Eyes and Yawns, Fingernails & Fingerprints
- Chapter 39 – 11 Weeks: Absorbs Glucose and Water
- Chapter 40 – 3 to 4 Months (12 to 16 Weeks): Taste Buds, Jaw Motion, Rooting Reflex, Quickening
- Chapter 41 – 4 to 5 Months (16 to 20 Weeks): Stress Response, Vernix Caseosa, Circadian Rhythms
- Chapter 42 – 5 to 6 Months (20 to 24 Weeks): Responds to Sound; Hair and Skin; Age of Viability
- Chapter 43 – 6 to 7 Months (24 to 28 Weeks): Blink-Startle; Pupils Respond to Light; Smell and Taste
- Chapter 44 – 7 to 8 Months (28 to 32 Weeks): Sound Discrimination, Behavioral States
- Chapter 45 – 8 to 9 Months (32 to 36 Weeks): Alveoli Formation, Firm Grasp, Taste Preferences
- Chapter 46 – 9 Months to Birth (36 Weeks through Birth)
|At 8 weeks the brain
is highly complex
and constitutes almost half of
the embryo's total body weight.
Growth continues at an extraordinary rate.
|By 8 weeks, 75% of embryos exhibit right-hand dominance. The remainder is equally divided between left-handed dominance and no preference. This is the earliest evidence of right- or left-handed behavior.|
|Pediatric textbooks describe
the ability to "roll over"
10 to 20 weeks after birth.
However, this impressive
is displayed much earlier
in the low-gravity environment
of the fluid-filled
Only the lack
of strength required
to overcome the higher
outside the uterus prevents
newborns from rolling over.
|The embryo is becoming
more physically active
during this time.
Motions may be slow or rapid, single or repetitive, spontaneous or reflexive.
Head rotation, neck extension, and hand-to-face contact occur more often.
|Touching the embryo elicits squinting, jaw movement, grasping motions, and toe pointing.|
|Between 7 and 8 weeks, the upper and lower eyelids rapidly grow over the eyes and partially fuse together.|
|Although there is no air
in the uterus,
the embryo displays intermittent
breathing motions by 8 weeks.
|By this time,
kidneys produce urine
which is released
into the amniotic fluid.
In male embryos, the developing testes begin to produce and release testosterone.
|The bones, joints,
and blood vessels
of the limbs
those in adults.
By 8 weeks the epidermis, or outer skin, becomes a multi-layered membrane, losing much of its transparency.
Eyebrows grow as hair appears around the mouth.
|Eight weeks marks the end
of the embryonic period.
During this time, the human embryo has grown from a single cell into the nearly 1 billion cells which form over 4,000 distinct anatomic structures.
The embryo now possesses more than 90% of the structures found in adults.