development nature vs. nurture continuity vs. discontinuity
TRANSCRIPT
Prenatal Development
• Begins with conception– When fertilization creates a zygote (one celled
organism)
• Ends with birth– Rapid rate of physical development (more so
than any other growth stage in life)
Physical Development: Prenatal
• Cephalocaudal – head to tail development
• Proximodistal – center outward development
Embryonic Stage
• 2 weeks to end of 2nd month– Most vital organs and bodily systems will form in
developing organism– Typically embryo is an inch long, but resembles
human with legs, arms, eyes, ears
** super important stage, if anything happens in this stage, it could be devastating
most miscarriages happen here, most birth defects occur here
Fetal Stage
• 2 months thru birth– Muscles and bones form– Fetus capable of physical mov’t– Hearing becomes functional
• During final 3 months, brain function starts– Respiratory and digestive systems mature
Threshold of Viability
• Ability for baby to survive at premature birth– Premature babies often experience a wide
range of developmental problems
Viability Laws
• Roe v. Wade– Must follow state legislation
• Most abortions will happen before the stage of viability (different weeks, depending on state laws)– Abortions after viability are rare, statistically
Environmental Factors and Prenatal Development
• Developing organism and mother are linked thru placenta– Mother = mother and fetus
• teratogens – substances that cause birth defects
Alcohol
• Fetal alcohol syndrome – collection of congenital (inborn) problems associated with excessive alcohol use during pregnancy– Microcephaly (small head)– Heart defects– Irritability– Hyperactivity– Delayed mental and motor development– Low birth weight– Mental retardation
Other teratogens
• Tobacco – miscarriages, stillbirth, low birth weight
• Heroin – baby born addicted to narcotics, premature death, cognitive defects
• Cocaine – birth complications, cognitive defects thru childhood
Maternal Illness and Exposure to Toxins
• Immune system matures late in prenatal period– Measles, mumps, rubella, syphilis, chicken pox (all
depends on when mother contracted the illness)
– HIV/AIDS – may occur prenatally through placenta, during delivery, breastfeeding
• Mid 1990’s, about 20-30% passed HIV to babies• Improved antiretroviral drugs and better prenatal care has
reduced that figure to 2% in the US