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 grade 3. Implantation - attachment of the zygote to the uterine wall (10 period later founding) * Blastocyst - inner cells (embryo) * Trophoblast - outer layer (placenta/ umbilical cord cord - life erects organizations) B. Embryonic Period - 2 to 8 weeks after conception 1. Cell differentiation intensifies, support systems for cells form and organs progresss 2. committed zygote becomes embryo * entoblast (digestive/respiratory systems) * Mesoderm (circulatory system, bones, muscles, excretory system, rejoinder system) * Ectoderm (nervous system sensory receptors, skin parts such as bull and nails) C. Fetal Period - 8 weeks after conception until take 1. Fetal size increases and organs start functioning 2. Reflexes appear and thither is sexual differentiation D. Miscarriage and Abortion 1. just about occur within 1st trimester (chromosomal abnormal ities) 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 miscarriage for every 2 stemmas * cast-off(prenominal) pregnancies stressful for woman regardless of how it is mulish * Psychological effects of abortion include relief and guilt trip (usually mild and disappears) * Women with previous psychiatrical problems more likely to convey adverse effects II. Teratology and Hazards to Prenatal Development A. Teratogen - whatever doer that yards birth defects 1.

Environmental Hazards * Radiation (chromo somal abnormalities) * Pollutants & toxi! c wastes (lead, pesticides, ascorbic acid dioxide, mercury dangerous to fetus) * Drugs Thalidomide - prescribed in 1960s for morning indisposition (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 calumniatory 2. Maternal diseases can cross the placenta barrier and cause birth defects - Rubella (German measles)... If you want to get a bountiful essay, enounce it on our website: BestEssayCheap.com

If you want to get a full essay, visit our page: cheap essay