Changes

====Closure of the Ductus Arteriosus====

====Closure of the Ductus Arteriosus====

The ductus arteriosus is a muscular artery and immediately after birth, contraction of the musculature closes the shunt. Factors which may contribute to the physiological closure of the ductus arteriosus include the increased oxygen content of the blood passing through it and the production of bradykinin, which causes smooth muscle contraction. This physiological closure causes blood to be directed from the pulmonary arteries to the now functioning lungs.  Anatomical closure takes about two months and occurs by infolding of the endothelium and proliferation of the subintimal connective tissue layer.

The ductus arteriosus is a muscular artery and immediately after birth, contraction of the musculature closes the shunt. Factors which may contribute to the physiological closure of the ductus arteriosus include the increased oxygen content of the blood passing through it and the production of bradykinin, which causes smooth muscle contraction. This physiological closure causes blood to be directed from the pulmonary arteries to the now functioning lungs.  Anatomical closure takes about two months and occurs by infolding of the endothelium and proliferation of the subintimal connective tissue layer. The residual ligament is termed the ligamentum arteriosum.