Root of pulmonary trunk

The root of the pulmonary trunk is the segment of the pulmonary artery that begins where the right ventricular outflow tract transitions into the pulmonary artery, and extends to the sinotubular junction. It is characterized by the presence of the pulmonary valve and its associated sinuses.

The pulmonary root is supported proximally by the free-standing right ventricular infundibulum, which provides a sleeve of myocardium beneath the fibroelastic walls of the pulmonary sinuses. The valve leaflets are attached in a semilunar fashion across the junction, delimiting the extent of the valvular sinuses.