NUR 349 Lecture Notes - Lecture 12: Patent Ductus Arteriosus, Atrial Septal Defect, Molloy College
Document Summary
Blood leaves the placenta via the umbilical vein (oxygenated & nutrient rich blood) and enters the fetus. After circulating through the fetus, blood returns to placenta through umbilical arteries (high in carbon dioxide and waste products) Three shunts divert most circulating blood away from lungs and liver. Shunts majority of blood flow of the umbilical vein directly to inferior vena cava. Allows blood to enter the l atrium from r atrium. Allows blood from the right ventricle to bypass fluid filled fetal lungs. Heart rate: high to low high heart rate to keep up with metabolic demands. Blood pressure: low to high increases as heart develops. Pulse oximetry: amount of oxygen available for tissue delivery. If untreated, pulmonary overcirculation leads to chf, pulmonary hypertension, and eventually death. Can be closed with medication, devices, or surgery. Opening in atrial septum that permits left-to-right shunting of blood. Opening in ventricular septum permits left-to-right shunting of blood.
