The pulmonary valve is located between the right ventricle and the pulmonary trunk to prevent the backflow of blood. Each flap is thickest at its margin. Here, it contains a small fibrous nodule in its middle, the nodule of the semilunar valve. From this nodule, fibers radiate to the attached base of the flap. When the opening is closed by these flaps, the nodules of the semilunar valve come together and fill up a triangular opening. Behind each valve-flap the artery bulges slightly. This forms the aortic sinus. Near the edge, a thin crescentic area is seen on each sides of the nodule of the semilunar valve. This area is called the lunula and corresponds to the area of contact of the valves.

Valva trunci pulmonalis

Valve du tronc pulmonaire