Term
| acts as a fetal lung during gestation of the fetus |
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Definition
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Term
| where does exchange ooccur in fetal circulation? |
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Definition
| the fetus circulation projects villi containing brances of the umbilical arteries and veins into a lake a maternal blood |
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Term
| True/ false the fetal gas exchange is more efficient than lung gas exchange |
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Definition
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Term
| the umbilical arteries are equivalent to what artery that carries venous blood |
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Definition
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Term
| the umbilical veins are equivalent to what vein that carries arterial blood |
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Definition
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Term
| Why is the PO2 gradient from maternal to fetal blood so large |
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Definition
| its caused by the poor efficiency of diffusion |
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Term
| how are PCO2 and pH gradients improved between the fetus and the maternal blood |
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Definition
| maternal hyperventilation |
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Term
| the 3 reasons that in spite the low fetal blood PO2 , the fetus has reasonable oxygen delivery |
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Definition
the HbF delivers oxygen more effectively that HbA
the fetus has higher RBC mass to promote oxygen delivery
the higher CO2 level in the fetus reduces the affinity of Hb for oxygen (promoted O2 delivery- Bohr effect) |
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Term
| brings oxygenated blood from placenta to the heart bypassing the liver |
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Definition
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Term
| Shunts oxygenated placental blood from the inferior vena cava through the right atria into the left atria |
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Definition
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Term
| less oxygenated blood from the superior vena cava enters the right heart, pulmonary artery, and bypasses the lungs |
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Definition
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Term
| what happens during the first fetal breath? |
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Definition
there is a very significant negative pressure, expanding the lugns and lowering the pulmonary vascular resistance to 20% of the fetal level.
COnversion to low pressure pulmonary and high pressure arterial promotes the closing of shunts |
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Term
| humeral factor that plays a role in shunt closing |
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Definition
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Term
| closes in 1-3 hours after birth, due to the closure of smooth muscle but the mechanism is poorly understood. |
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Definition
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Term
| Decreased pulmonary vascular resistance lowers right atrial pressure and blood returning from the lungs raises pressure in left atrium, closes this shunt |
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Definition
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Term
| this hormone constricts he umbilical vessels and the ductus arteriosis and dialates the pulmonary vessels |
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Definition
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Term
| this chemical keeps the ductus arteriosis open prior to birth and has a role in preventing pulmonary hypertension |
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Definition
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Term
| All the oxygenated blood gets sent back to the lungs. the blood flows like normal until it gets to the aorta, then it shunted back to the pulmonary artery. results in enlargement of the left atria, left ventricle (because the heart must pump hard to bypass the shunt) and the aorta |
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Definition
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Term
| there is a defect in the wall of the atria, so the blood flows from the left side into the right side of the heart. results in enlarged right atria, right ventricle, and pulmonary artery |
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Definition
atrial septal defect
aka
ostium secumdum type A |
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Term
| there is defect in the cushion of the heart, causing blood from the left ventricle to be shunted to the right ventricle. this causes the left ventricle ans atria to enlarge |
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Definition
| ventricular septal defect |
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