1. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Chapter 4 Prenatal Development and Birth

2. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Chapter 4- Prenatal Development Time of fastest development in life span Environment extremely important Conception –Ova (eggs) travels from ovary to uterus –Penetration by 1 of 300-500 sperm –Outcome: single-celled ZYGOTE (fertilized egg)

3. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Prenatal Development and the Zygote

4. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Prenatal Stages Germinal period: days 1-14 (0 - 2 weeks) –Zygote’s implantation into uterine wall: 1/2 are successful –Zygote divides many times through mitosis to form blastocyst (about 150 cells) –Miscarriage: 15% (recognized) to 50% Embryonic period: 3 rd to 8 th week (3 rd week - 2 nd month) –Organogenesis – every major organ takes shape –Sexual differentiation – begins during 7 th & 8 th week (sex genes impact formation of testes or ovaries)

5. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Outer Layer of Blastocyst (150 cells) forms: Amnion – a watertight membrane that fills with fluid that cushions and protects the embryo Chorion – a membrane that surrounds the amnion and attaches rootlike extensions called villi to the uterine lining to gather nourishment for the embryo. The chorion eventually becomes the lining of the placenta Placenta – tissue fed by mother’s blood vessels and connected to the embryo by the umbilical cord Umbilical cord – connection between embryo and mother through which nutrients and wastes are exchanged Placental barrier – protects developing child from many harmful substances, and allows small molecules exchanged between mother and embryo

6. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Inner cell mass of blastocyst forms : Ectoderm – eventually forms the central nervous system (brain and spinal cord) Mesoderm – muscle tissue, cartilage, bone, heart, arteries, kidneys, and gonads Endoderm – gastrointestinal tract, lungs, and bladder Neural plate forms neural tube (bottom is spinal cord) Top of tube forms into forebrain, midbrain, hindbrain

7. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Figure 4.3

8. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Fetal period: 9 th week – birth –Proliferation of neurons (250,000 per minute) – Migration of neurons –Differentiation of stem cells –Ends in tremendous brain development Age of viability – around 24-25 weeks (fetus has possibility of surviving outside uterus) 3 rd Trimester – myelination (insulating cover that increases speed of transmission)

9. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4

10. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Prenatal Development and the Newborn 40 days 45 days 2 months 4 months

11. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Prenatal Environment Reciprocal influence –Person and environment –Good and bad influences important Teratogen: harmful environmental agent –Harms the developing fetus –Critical Period: Organogenesis –Dosage & duration –Genetic make-up: susceptibility

12. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Teratogens-Drugs Thalidomide (for morning sickness) –All or parts of limbs missing Tobacco: miscarriage, low birth weight, SIDS, slows fetal growth Alcohol: FAS –Small, facial deformities, retardation Cocaine: Processing difficulties

13. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Figure 4.6

14. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 FETAL ALCOHOL SYNDROME

15. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Teratogens - Diseases Rubella (German Measles) –Blind, deaf, heart, brain Syphilis:miscarriage, blind, deaf, heart, brain –After 18 th week AIDS mothers transmit to babies (15%-35%) –Prenatally, perinatally, postnatally

16. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Teratogens – Environmental Hazards Radiation: MR, leukemia, cancer, mutations, spontaneous abortions, etc. –Avoid X-rays when pregnant Pollutants –In air and water – Lead - MR (also postnatally) Anoxia – Oxygen shortage – brain cells die – can cause mental retardation or cerebral palsy (difficulty controlling muscle movements and possibility of MR)

17. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4

18. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4

19. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4

20. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 Postnatal Depression Baby Blues, mild, common Postpartum depression: 1/10 –Previous depression common Children of depressed mothers –Insecurely attached, less responsive –Negative to other children

21. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 APGAR TEST Provides a quick assessment of the newborn’s: 1) Heart rate (0-2 points) 2) Respiratory effort (0-2 points) 3) Muscle tone (0-2 points) 4) Color (0-2 points) 5) Reflex irritability (0-2 points) The Apgar test is given immediately and 5 minutes after birth 7 or higher = good shape 4 or lower = at risk

22. Life-Span Human Development, Fifth Edition, Carol K. Sigelman and Elizabeth A. Rider Chapter 4 The Neonatal Environment Culture, early socialization, health status –E.g., low birth-weight babies (8% in US) Less than 5 1/2 lbs or 2500 grams Strongly linked to low SES Environment: neonatal intensive care Risk: blindness, deafness, CP, autism, cognitive, and later academic problems Parenting must be attentive, responsive