Foramen Secundum - Closing During Birth

Closing During Birth

To provide proper blood flow as a a newborn, the foramen secundum and foramen ovale must close when birth occurs. Since the lungs now require a significant amount of blood flow, the vessels going to and from the lungs undergo dilation. While the pulmonary artery and pulmonary veins are dilating, the umbilical artery and umbilical vein are severed due to the cutting of the umbilical cord, or the funiculus umbilicalis. This combination results in a reversal of pressure differences between the atria and the septum primum is permanently forced against the septum secundum. This holds true even during atrial diastole, when the pressure is significantly less than atrial systole.

Read more about this topic:  Foramen Secundum

Famous quotes containing the words closing and/or birth:

    It is closing time in the gardens of the West and from now on an artist will be judged only by the resonance of his solitude or the quality of his despair.
    Cyril Connolly (1903–1974)

    When we consider how much climate contributes to the happiness of our condition, by the fine sensation it excites, and the productions it is the parent of, we have reason to value highly the accident of birth in such a one as that of Virginia.
    Thomas Jefferson (1743–1826)