Embryology

Question 1

Cardiac and respiratory sequence at birth (7)

Answer 1

Lungs expand
Reduced pulmonary vascular resistance
Increased pulmonary artery blood flow
Umbilical artery shuts
Reversal of blood flow through ductus arteriosus
Increased left atrial pressure
Foramen ovale shuts

Question 2

Problem in transposition of the great arteries

Answer 2

= failure of the aorticopulmonary arch to spiral during septation