Anterior Semilunar Leaflet of the Pulmonary Valve in Transverse Section

Description

Centered in a transverse section through the right ventricular outflow tract, the pulmonic valve sits at the junction of the infundibulum and the pulmonary trunk. The anterior semilunar leaflet (anterior cusp) rises from the valve annulus and curves superiorly toward the sinotubular junction, with its free margin meeting the adjacent right and left leaflets at the commissures. The pulmonary trunk lies superior and slightly anterior to the right ventricle in this cut plane, while the valve orifice occupies the central lumen framed by the three cusps. Fine relationships stand out: each commissure anchors at the arterial wall, and the leaflet body spans from the annulus (inferior) to the coaptation line (superior). Commissural anatomy matters because the pulmonary valve is frequently crossed and manipulated during congenital heart procedures, and small errors in understanding cusp orientation can translate into residual pulmonary regurgitation. After repair of tetralogy of Fallot or valvotomy for pulmonary stenosis, clinicians often evaluate cusp coaptation and commissural symmetry on echocardiography, and this transverse perspective maps directly to short-axis imaging at the level of the valve. A clean view of the anterior cusp also helps explain why leaflet tears or post-intervention scarring tend to track toward commissural attachment points. Small structure, big consequences. Use this illustration when you need a concise teaching image of pulmonic valve cusps and commissures for cardiovascular anatomy labs, congenital cardiology lectures, or figure panels discussing RVOT reconstruction and pulmonary valve-sparing strategies. It also fits surgical atlases and radiology education materials that correlate transverse gross anatomy with parasternal short-axis echocardiographic views of the pulmonary valve and main pulmonary artery. Anatomical accuracy verified by SciePro's Medical Advisory Board.