pulmonary valve (anatomy)

Last reviewed 01/2018

The pulmonary valve is the heart valve between the right ventricle and the pulmonary trunk. It consists of three semi-lunar leaflets or cusps which project into the pulmonary trunk:

  • anterior
  • left
  • right

It lies slightly anterosuperior to the aortic valve at the superior end of the infundibulum of the right ventricle; this is roughly the level of the left third costal cartilage. Its plane faces posterosuperior and to the left. The diameter of the valve is 2-3cm.

Each valve cusp is characterised by:

  • a central layer of collagen, the lamina fibrosa
  • a thickening of the lamina fibrosa at the free margin of each leaflet - the nodulus
  • regions lateral to the nodulus of each valve termed the lunules
  • a layer of endocardium completely covering the valve
  • an attachment between the lamina fibrosa and the pulmonary valve annulus, part of the fibrous skeleton of the heart
  • a dilation of the wall of the pulmonary trunk immediately superior to each cusp - the sinuses of Valsalva; each sinus fills with blood, so preventing the valve leaflet from adhering to the wall of the pulmonary trunk with consequent valvular incompetence