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The fetal circulation is composed of the placenta, umbilical blood vessels encapsulated by the umbilical cord, heart and systemic blood vessels. A major difference between the fetal circulation and postnatal circulation is that the lungs are not used during the fetal stage resulting in the presence of shunts to move oxygenated blood and ...
The "E" series of prostaglandins are responsible for maintaining the openness of the ductus arteriosus (by dilation of vascular smooth muscle) throughout the fetal period. [3] Prostaglandin E2 (PGE 2 ), produced by both the placenta and the DA itself, is the most potent of the E prostaglandins, but prostaglandin E1 (PGE 1 ) also has a role in ...
The unpaired umbilical vein carries oxygen and nutrient rich blood derived from fetal-maternal blood exchange at the chorionic villi.More than two-thirds of fetal hepatic circulation is via the main portal vein, while the remainder is shunted from the left portal vein via the ductus venosus to the inferior vena cava, eventually being delivered to the fetal right atrium.
The endocardial cushions are thought to arise from a subset of endothelial cells that undergo epithelial-mesenchymal transition, a process whereby these cells break cell-to-cell contacts and migrate into the cardiac jelly (towards the interior of the heart tube).
Lung ventilation also extends the so far convoluted, shrunk pulmonary vessels, also contributing to the quick and marked drop in the pulmonary vascular resistance. As a result, much higher proportion of the right ventricle output flows into the pulmonary vessels than into the systemic circulation through the ductus arteriosus.
Fetal hemoglobin, or foetal haemoglobin (also hemoglobin F, HbF, or α 2 γ 2) is the main oxygen carrier protein in the human fetus.Hemoglobin F is found in fetal red blood cells, and is involved in transporting oxygen from the mother's bloodstream to organs and tissues in the fetus.
Umbilical cord compression can result from, for example, entanglement of the cord, [16] a knot in the cord, [16] or a nuchal cord, [16] (which is the wrapping of the umbilical cord around the fetal neck) [17] but these conditions do not always cause obstruction of fetal circulation. Velamentous cord insertion; Single umbilical artery; Umbilical ...
Persistent fetal circulation is a condition caused by a failure in the systemic circulation and pulmonary circulation to convert from the antenatal circulation pattern to the "normal" pattern. Infants experience a high mean arterial pulmonary artery pressure and a high afterload at the right ventricle.