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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:
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
Last reviewed 01/2018