Stage 1, Germinal Period
8-10 days, zygote, feritilization, and implantation, amnion forms, placenta forms
amnion
a thing, tough, transparent membrane that holds the amniotic fluid, and surrounds the embryo
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placenta
an organ that is made up of tissue from both the mother and the fetus that serves as a barrier and a filter btwn their bloodstream, umbilical chord is attached
umbilical chord
a flexible helical structure containing blood vessels that connects the developing organism to the placenta
Plasticity vs Specialization
totipotent cells-any cell can become anything (stem cells), specialization multipotent cells- the cell transforms to the surrounding cells
Stage 2, Embryonic Period
2-8 weeks , embryo, forming major systems, a sensitive period (harmful to environmental factors), neural tube at 26 days (spine +brain become nervous system), 6 weeks arm buds and eyes form, takes cephalocaudal trend
cephalocaudal trend
from head to tail growth
Stage 3, Fetal stage
9th week til birth, fetus, all basic tissues are formed, fetus grows rapidly in size, age of viability
Teratogens
abnormalities from environmental factors that harm the normal development of the baby determined by dose, heredity, sum total, and timing.
caffeine (in large does)
spontaneous abortion, low birth weight ( messes with placenta and nutritent flow)
tobacco
Deprives fetus of oxygen and nutrition, low birth weight, associated with SIDS ( sudden infant death syndrome w/in 1st 3 months)
alcohol
3 drinks or more on a single occasion, affects physical and mental development, FAS ( fetal alcohol syndrome): mentally retarded, poor motor/attention/memory, lang deficits, overactivity, slow physical growth.
viable
at 7months or 28 weeks, to live outside the womb, digestive and respiratory systems working, born 1.5lbs able to survive
Prenatal learning (hearing) Salk
Salk: study of newborns, heart beating, and weight gain, found:infants react positively to stimuli similar to those in prenatal stages
prenatal learning DeCasper & Spence
Mothers read a story during pregnancy to
fetus, tested newborsn 2/3 days old, read old and new story, prefered old story, and sucking rate went with diction of words