PSYC 205 Lecture Notes - Prenatal Development, Amniotic Sac, Umbilical Cord
Up Series
Gathered 14 children in Britain and interviewed them at age 7 and after which, they continued
to interview them every 7 years
Phylogenetic continuity - because of our common evolutionary history, humans share many
characteristics and developmental processes with other living things
Sperm that carry Y chromosome - more likely to get fertilized because they are lighter and swim faster.
But more likely to die than females because of complications
3 stages of prenatal development
Germinal Stage -
oLasts approx 2 weeks
oStarts with fertilization of egg in fallopian tube (conception)
oEnds with attachment to uterine wall
oMajor achievements -
cell division is rapid, increases to upto 2x, blastocyst - hollowed out sphere of
cells
Attachment to uterine wall - when this occurs, support systems start to develop.
An amnion forms around the organism which is filled with amniotic fluid that provides
cushioning and accurate temperature for babies growth. By 2nd week, placenta
(chorion eventually forms a placenta) starts to form that provides food and water for
nourishment. Very delicate time - 45% of pregnancies don't make it to 3rd week
Embryonic Stage -
oLasts from 3rd to 8th week
oStarts with attachment to uterine wall - dependence on mother is signified
oThe blastocyst (hollowed out sphere) will collapse and form a tube (neutral tube) which
will eventually become the head and spinal cord
oDevelopment of support system - amniotic sac, placenta, and umbilical cord
oEnd marked by formation of bone cells
oSee fingers form (even though they are webbed), there is a tail that will go away, eyes
are sealed shut till 7 months because they are very sensitive
oMajor achievements
Lots of growth is going on - embryo quadruples in size
Organs begin to form and operate
Specifically critical periods and is influenced by teratogens
(environmental substances that can cause harm during prenatal period such as
nicotine, alcohol, drugs) and most susceptible during embryonic stage - each
organ has a specific critical period of time where it can be influenced by a
specific kind of teratogen
Begin to see movement on an ultrasound
Fetal Stage -
oLongest stage in terms of time - 8th week to ~38 weeks
oStarts at formation of bone cells
oEnds at birth
oMajor achievements
Lots of growth in terms of size and development of organs
Movement is continuing and can be felt by the mother
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Document Summary
Gathered 14 children in britain and interviewed them at age 7 and after which, they continued to interview them every 7 years. Phylogenetic continuity - because of our common evolutionary history, humans share many characteristics and developmental processes with other living things. Sperm that carry y chromosome - more likely to get fertilized because they are lighter and swim faster. But more likely to die than females because of complications. Starts with fertilization of egg in fallopian tube (conception) Ends with attachment to uterine wall: major achievements - cell division is rapid, increases to upto 2x, blastocyst - hollowed out sphere of cells. Attachment to uterine wall - when this occurs, support systems start to develop. An amnion forms around the organism which is filled with amniotic fluid that provides cushioning and accurate temperature for babies growth. By 2nd week, placenta (chorion eventually forms a placenta) starts to form that provides food and water for nourishment.
