2 THEMES: TRANSITION AND CONTINUITY HUMAN DEVELOPMENT ACROSS THE LIFE SPAN

DEVELOPMENT DEF: sequence of age-related changes that occur as a person progresses from conception to death Fairly orderly Cumulative Both biological and behavioral changes

PRENATAL DEVELOPMENT Development begins with conception---fertilization creating a zygote Prenatal period ends at birth

GERMINAL STAGE 1. Germinal stage: 1 st phase; 1 st 2 weeks after conception Begins w/creation of zygote Within 36 hours: rapid cell division 7 th day: cell mass begins implanting to uterine wall Placenta forms

EMBRYONIC STAGE DEF: 2 nd stage; starts at 2 weeks and ends after 2 nd month Most vital organs and bodily systems begin to form Very vulnerable---most miscarriages occur in this stage

FETAL STAGE DEF: 3 rd stage; lasting from 2 months to birth Rapid bodily growth---muscles and bones begin to form Organs begin to function 3 rd month: sex organs begin to develop Final 3 months: brain cells multiply rapidly; respiratory and digestive system mature

AGE OF VIABILITY DEF: the age at which a baby can survive in the event of a premature birth Usually between 22 and 26 weeks after conception

ENVIRONMENTAL FACTORS AND PRENATAL DEVELOPMENT Nutrition is important Dietary deficits have shown correlation to apathy, irritability, and reduced immunity to infectious diseases

ENVIRONMENTAL FACTORS CONTINUED Most drugs consumed by mother can pass through placental membrane ALL recreational drugs are harmful Cocaine: heart abnormalities, brain seizures most common Prescription drugs: effects vary based on drug, dose, and prenatal stage

ALCOHOL AND TOBACCO Fetal Alcohol Syndrome: collection of congenital problems assoc. w/excessive drinking during pregnancy Tobacco: smoking during pregnancy reduces flow of oxygen and nutrients to the fetus

MATERNAL ILLNESS Fetus is vulnerable to disease---placenta does some filtering Rubella, syphilis, cholera, smallpox, mumps, and severe flu are hazardous Genital herpes and AIDS can transmit to offspring

PRENATAL HEALTH CARE Most prenatal dangers are preventable Poor health care is prominent in racial minorities USA ranks 41 st in infant mortality rate