Opening of the pulmonary artery
（重定向自Ostium trunci pulmonalis）
The opening of the pulmonary artery (or trunk) is circular in form, and situated at the summit of the conus arteriosus, close to the ventricular septum.
It is placed above and to the left of the atrioventricular opening, and is guarded by the pulmonary semilunar valves.