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Unformatted text preview: Foramen ovali : closes : by adhesion of upper part of septum primum to the lower part of septum secundum • septum primum inferior to the foramen ovali : fossa ovalis • Lower margin of septum secondum/crista dividens : limbus
• Ductus arteriosus : ligamentum arteriosum • Umbilical arteries : the medial umbilical ligaments : superior vesical arteries. Problems in the changes of the vascular shunts after birth: Patent ductus arteriosus.
- functional closure ---soon after birth in full term infants
- if patent -- shunts aortic blood into pulmonary trunk
- common congenital anomaly associated with
maternal rubella infection during early pregnancy
- common in premature infants and infants born at high altitudes-due to hypoxia and immaturity Embryological basis of PDA – failure of D.A to involute.
- failure of muscular wall to contract to form ligamentum
- large pressure differences in pulmonary and aortic blood
pressures, Eg. Coarctation of aorta,
transposition of great arteries
- hypoxia, prematurity, high altitude
- prostaglandins - relaxes smooth muscle.
- bradykinin - contraction of smooth muscle Patent foramen ovali.
Failure of upper part of septum primum to fuse with lower part
of septum secondum Atrial septal defects will be
discussed in detail –
In the lecture on
development of the heart. What is lunate impression? Impression on the left atrial aspect of the site of oval foramen. Bless you. To God be the glory....
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- Winter '14