Prenatal Development Psych 150 PDF

Psych 150 – Developmental Psychology Prenatal Development  Prenatal Development Never again in his life, in so brief a period will this human being grow so rapidly or so much, or develop in so many directions, as he does between conception and birth… During this critical period,...

Psych 150 – Developmental Psychology Prenatal Development  Prenatal Development Never again in his life, in so brief a period will this human being grow so rapidly or so much, or develop in so many directions, as he does between conception and birth… During this critical period, the development of the human body exhibits the most perfect timing and the most elaborate correlations that we ever display in our entire lives. The building and launching of a satellite, involving thousands of people and hundreds of electronic devices, is not nearly so complex an operation as the building and launching of a human being - Ashley Montagu, Anthropologist (1964) Conception and Implantation Figure 3.1 Table 2-5 Stages of the Prenatal Period Germinal Stage Fertilization → 2 weeks Shortest stage Fertilized egg now called a blastocyst Travels to and implants in the uterus Characterized by methodical cell division With division comes cell specialization Embryonic Stage 2 weeks → 8 weeks Organism firmly secures to uterus and called an embryo Development of major organs and basic anatomy Three distinct layers that ultimately form different set of structures Ectoderm Endoderm Mesoderm Fetal Stage 8 weeks → Birth Formally starts when differentiation of major organs has occurred Organism now called a fetus Characterized by rapid development – Organs become more differentiated and begin working – Interconnections between body parts become more complex and integrated – Brain becomes more sophisticated  Period of the Fetus Begins at third month Second trimester – fetal movement felt Third trimester – age of viability 22–26 weeks Figure 2.13 Body Proportions During the fetal stage, the proportions of the body change dramatically. At two months, the head represents about half the fetus, but by the time of birth, it is one-quarter of its total size.  Sensitive Periods in Prenatal Development Figure 3.2  Teratogen Substances Drugs – prescription – nonprescription – illegal Tobacco Alcohol Radiation Pollution Absolute Family Effects of Teratogens Crack/Cocaine Exposure Figure 2.15 Teratogen Sensitivity Depending on their state of development, some parts of the body vary in their sensitivity to teratogens.  Maternal Factors in Healthy Prenatal Development Diet Age Prenatal Support General health Infectious diseases Nutrition Emotional stress Rh blood factor  Complications and Maternal Age Figure 3.4. Father’s Prenatal Influence Relatively little research Tobacco use Drug use Alcohol use Treatment of mother