PSY 232 Chapter Notes - Chapter 2: Muscle Tone, Prenatal Development, Infertility
20 Mar 2018
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Document Summary
Down syndrome aka trisomy 21 nondisjunction (cell division error. A person who inherits one copy of the gene always gets the disease. Child gets inheriting two copies of the abnormal gene that causes the disorder. Mass has not fully attached to the wall of the uterus zygote. Within 36 hours the fertilization ovum, now a single cell. The embryonic stage: week 3 to week 8. Lasts only 6 weeks most fast-paced period of development. Massive growth and refinements; brain develops; live birth is possible at 22-24 weeks. Teratogens can impair growth affects the brain and so cause developmental disorders example; infectious disease; a medication; a recreational drug; environmental hazards such as radio pollution. Earliest date at which babies possibly can live; 22 to 23 weeks. Fetal alcohol syndrome qualities far-smaller-than-normal birth weight; an abnormally small brain; facial abnormalities (such as flat face) and developmental disorders. Chronic villus samplining first trimester: needle in the placenta to take out fluid.
