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30 Cards in this Set
- Front
- Back
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Time of the embryonic period?
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conception to end of 8th week
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What develops during the embryonic period?
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all major organ systems
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What is the effect of drug use during the embryonic period?
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missing kidneys
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Time of the fetal period
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from the 9th week until delivery
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What develops during the fetal period?
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increase in cell number and size, and organ systems structually remodel to "normal"
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What is the effect of drug use during the fetal period?
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may cause organs not to work as well as they should
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How long does it take the zygote to reach the uterus?
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3-4 days
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By what day does a blastocyte form?
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by day 6
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How long after reaching the uterus does it take for the embryo to implant into the wall?
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24-48 hours
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Week 1 events (4)
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-Fertililzation occurs
-zygote reaches uterus -blastocyte forms -embryo implantation |
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Week 2 events (4)
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-implantation complete
-uteroplacental circulation begins -embryo has 2 distinct layers -amnion begins to develop |
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The endoderm forms what structures? ectoderm?
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endoderm = internal
ectoderm = external |
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Week 3 events (4)
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-mesoderm appears
-neural tube and blood vessels appear -paired heart tubes begin to pump -mother misses first menstrual period |
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Week 4 events (4)
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-placenta forms
-arm and leg buds appear -embryo folds into human-like shape -neural folds fuse |
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Week 5 events (4)
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-peripheral motor and sensory nerves begin to form
-primitive mouth develops -digital rays on hands/feet -lens placodes appear |
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Week 6 events
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-primitive nose is obvious
-primary palate forms |
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Week 7 events
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-embyronic liver takes over blood cell production
-baby has its own blood type -mouth and tongue form -external ear forms -eyelids begin to form |
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Week 8 events
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-ovaries and testes distinguishable
-axons and dendrites growth rates increases significantly -legs, arms, fingers developed -amniotic sac developed -muscle contractions first appear |
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Week 10 events
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-face is recognizably human
-nervous system becomes responsive -heart is almost completely developed -external genitalia are distinguishable -twenty teeth start to form in gum line |
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Weeks 12-14 events
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-lung development
-vocal cord development completes -brain fully developed and child can feel pain in general sense -mother may begin to feel movement -eyelids are formed |
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Weeks 20-24 events
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-considered lower limit of viability
-primitive alveoli have formed and surfactant production has begun (lungs could now be able to exchange gases) -child can now hear and recognize mother's voice -lanugo covers the child |
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Third trimester (Weeks 25-40) events
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-1st form of learning occurs
-wt triples and length doubles -body begins to store protein, fat, iron, and calcium -child sleeps about 90% of day -fetal movement increases in response to a sudden sound with a specific tone and decreases if the tone is repeated |
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What % of pregnancies end in a spontaneous abortion? What is mortaility most often due to?
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30%; chromosomal abnormalities or major structural abnormalities
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What type of abnormalities occur from teratogens during the embryonic period?
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major morphological abnormalities (thalidomide and limb malformation)
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What type of abnormalities occur from teratogens during the fetal period?
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physiological defects and only minor morphological abnormalities
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Teratogenic effects of alcohol
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-intrauterine growth retardation
-microcephaly -mental retardation -maxillary hypoplasia -thin upper lip -cardiac abnormalities |
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Teratogenic effects of coumarin derivatives
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-nasal hypoplasia
-calcific stippling of the secondary epiphysis -CNS abnormalities |
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Time period with highest risks associated with coumarin derivatives
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from the 8th to 14th weeks post-conception
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Teratogenic effects of ACE inhibitors
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-hemorrhagic foci found in renal cortex and medulla causing oligohydramnios, anuresis, hypotension, and death
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Are ACE inhibitors okay to use during the embryonic period?
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yes, ill effects have not been seen during first trimester
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