Pulmonary Trunk

Conus Arteriosus (Infundibulum)

The right ventricle extends as the Conus Arteriosus (Infundibulum), the smooth area of the Pulmonary Trunk below the level of the pulmonic valve. Above the level of the pulmonic valve the pulmonary trunk continues and gives rise to a right and left pulmonary artery. The right and left pulmonary arteries pass posterior and anterior to the arch of the aorta, respectively. The ductus arteriosus connects the left pulmonary artery to the concavity of the arch of the aorta.

There is both an anatomical and a physiological closure to the ductus arteriosus. Closure of the ductus arteriosus results in the ligamentum arteriosum.