The<unk>  is a conical pouch formed from the upper and left angle of the right ventricle, from which the pulmonary artery arises.
A tendinous band, which may be named the tendon of the<unk> , extends upward from the right atrioventricular fibrous ring and connects the posterior surface of the<unk>  to the aorta.  This is also called the infundibulum, and it is the entrance from the right ventricle into the pulmonary artery and pulmonary trunk.  The wall of the infundibulum is smooth.
Conus arteriosus
Ductus arteriosus
Atrioventricular canal
Interatrial septum
Aorticopulmonary septum
Aortic arches
Tricuspid valve
Descending aorta