Life-span development chap 4 notes

I. Prenatal Development A. Germinal Period - Conception to 2 weeks 1. Creation of the zygote 2. Continued cellular telephone piece 3. Implantation - attachment of the zygote to the uterine wall (10 board later founding) * Blastocyst - inner cells (embryo) * Trophoblast - outer layer (placenta/ umbilical cord cord - life jump outs frames) B. Embryonic Period - 2 to 8 weeks after conception 1. Cell differentiation intensifies, support systems for cells form and organs come forwards 2. committed zygote becomes embryo * endoderm (digestive/respiratory systems) * Mesoderm (circulatory system, bones, muscles, excretory system, rejoinder system) * Ectoderm (nervous system sensory receptors, skin parts such as hair and nails) C. Fetal Period - 8 weeks after conception until take in 1. Fetal size increases and organs start functioning 2. Reflexes appear and thither is sexual differentiation D. Miscarriage and Abortion 1. intimately occur within 1st trimester (chromosomal abnorma lities) 2. 15-20% pregnancies expiry in miscarriage * male fetuses more likely to miscarry 3. Abortions legal in U.S. until stamp out of 2nd semester * 1 spontaneous abortion for every 2 bring forths * cast-off(prenominal) pregnancies stressful for woman regardless of how it is obstinate * Psychological effects of abortion include relief and depravity (usually mild and disappears) * Women with previous psychiatrical problems more likely to meet adverse effects II. Teratology and Hazards to Prenatal Development A. Teratogen - whatever agent that yards birth defects 1.

Environmental Hazards * Radiation (chromosomal abnormalities) * Pollutants & toxic was! tes (lead, pesticides, ascorbic acidulated dioxide, mercury dangerous to fetus) * Drugs Thalidomide - prescribed in 1960s for morning illness (deformed babies) Cocaine/heroin (addiction/withdrawal symptoms/neurological defects) Alcohol (fetal alcoholic drink syndrome) Smoking (low birth weight, ADHD, wrong births, SIDS) Marijuana, antibiotics, excessive vitamins, antihistamines, aspirin, diet pills deleterious 2. Maternal diseases can cross the placenta barrier and cause birth defects - Rubella (German measles)... If you want to get a bountiful essay, dictate it on our website: OrderCustomPaper.com

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