Postnatal / Adult heart. Postnatal circulation. Fetal circulation. Lung bypasses in fetal circulation. Tubular heart. Division of truncus. Semilunar valves. Persistent truncus. Transposition of great vessels. Valve stenosis. Patent ductus arteriosus. Coarctation of the aorta. Formation of interatrial septum. Atrial septal defects (ASD). Formation of interventricular septum. Tetralogy of Fallot. Formation of atrioventricular valves. Congenital heart defects.