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25 Cards in this Set
- Front
- Back
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Developmental window of heart
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3-8 weeks
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What is the developmental push for primitive heart?
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No more nutrient gas gains by diffusion
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When does endocardial tube fuse together? What else happens by this time?
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By day 22; beats
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Role of bulbis cordis
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outlet of ventricles
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role of primitive ventricle
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inlet of ventricle
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sinus venosus becomes what?
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R atrium
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When does foramen primum close and septum secundum begin to develop?
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week 5
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What allows flow across foramen ovale?
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pressure gradient from L to R
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components of ventricular septation
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left and right bulbar ridges + muscular part of septum from bottom
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When do bulbar ridges form?
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5 weeks
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What two developmental areas does the aorticopulmonary septum divide?
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bulbus cordis (outlet of ventricles)
truncus arteriosus (aorta & pulm) |
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Two general components of valvular development
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endocardial cushions (wk 4)
valves (wk 7) |
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What two things shape valve development?
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programmed cell death, blood flow
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From common AV canal, how do cushions develop?
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cushions grow from superior, inferior, and lateral, leading to left and right AV canal
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3 shunts in fetal circulation
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ductus venosus
foramen ovale ductus arteriosus |
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Describe umbilical vein in fetus
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Carries highly oxygenated blood
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Ductus arteriosus directs blood where?
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When pumped from pulmonary, connects to aorta
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Where does a majority of the oxygen go in fetal circulation?
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head/neck (62%)
myocardium (9%) |
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What provides 2/3 of fetal circulation?
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right ventricle
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What diverts flow from lungs?
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Really high pressures (filled with amniotic fluid and vasocontricted without oxygen)
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Where is there a lower resistance, placenta or lungs?
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placenta
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Results of first breath?
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Mechanical inflation
inc pulmonary oxygen tension (clamping of cord to change pressures) |
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Which shunts are functionally closed at birth?
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foramen ovale
ductus venosus |
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When is there anatomic closure of ductus venosus?
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1 week
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When is there permanent anatomic closure of ductus arteriosus?
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4-8 weeks
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