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 cleav advance 3. Implantation - attachment of the zygote to the uterine wall (10 age later founding) * Blastocyst - inner cells (embryo) * Trophoblast - outer layer (placenta/umbilical cord cord cord - life mounts forms) B. Embryonic Period - 2 to 8 weeks after conception 1. Cell differentiation intensifies, support systems for cells form and organs counts 2. committed zygote becomes embryo * entoderm (digestive/respiratory systems) * Mesoderm (circulatory system, bones, muscles, excretory system, rejoinder system) * Ectoderm (nervous system sensory receptors, skin parts such as blur and nails) C. Fetal Period - 8 weeks after conception until race 1. Fetal size increases and organs start functioning 2. Reflexes appear and thither is sexual differentiation D. Miscarriage and Abortion 1. more or less occur within 1st trimester (chromosomal abnormalit ies) 2. 15-20% pregnancies expiry in abortion * male fetuses more likely to miscarry 3. Abortions legal in U.S. until stamp out of 2nd semester * 1 spontaneous abortion for every 2 stimulates * cast-off(prenominal) pregnancies stressful for woman regardless of how it is intractable * Psychological effects of abortion include relief and ill-doing (usually mild and disappears) * Women with previous psychiatrical problems more likely to mother 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 wastes (lead, pesticides, ascorbic unpleasant dioxide, mercury dangerous to fetus) * Drugs Thalidomide - prescribed in 1960s for morning ill humour (deformed babies) Cocaine/heroin (addiction/withdrawal symptoms/neurological defects) Alcohol (fetal inebriant syndrome) Smoking (low birth weight, ADHD, wrong births, SID S) Marijuana, antibiotics, excessive vitamin! s, antihistamines, aspirin, diet pills pestilential 2. Maternal diseases can cross the placenta barrier and cause birth defects - Rubella (German measles)... If you want to get a bountiful essay, score it on our website: BestEssayCheap.com

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