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Heart Valves (Photos)
https://sites.google.com/a/umich.edu/bluelink/resources/bluelink

Heart Valves (Photos)

Heart Valve Anatomy
We'll use standard names for the valve (cusps), but be aware that nomenclature varies based on author's preference for fetal or adult position and other considerations.
Semilunar Valves:
Comprise three cusps, aka, leaflets, that prevent backflow to the ventricles.
  • Pulmonary valve comprises an anterior, right, and left leaflet; they ensure unidirectional flow of deoxygenated blood from the right ventricle to the lungs.
  • Aortic valve comprises right coronary, left coronary, and posterior non-coronary leaflets; leaflet names reflect their relationships to the ostia of the coronary arteries. The aortic semilunar valve ensures unidirectional flow of oxygenated blood from the left ventricle to systemic circulation.
  • Trap blood within the sinuses of the aorta and pulmonary trunk.
During diastole, the semilunar valve leaflets fall open to trap blood in the sinuses, thus preventing backflow into the ventricles. The coronary arteries run into the right and left aortic sinuses.
  • Annulus is the ring-like network of fibrous tissue that attaches the leaflets to the vessel wall. It's not really a perfect circle of continuous fibrous tissue, but instead comprises elements that are dynamically responsive to heart contractions.
  • Nodule (aka, nodule of Arantius), is a thickened spot in the middle of the free edge of the leaflet.
  • Lunule is the free edge of the leaflet.
  • Commissures are where the leaflets attach to the wall.
  • Sinotubular junction passes through the commissures and signifies the transition from the sinus to the vessel.
Atrioventricular (AV) valves:
  • Bicuspid valve, aka, mitral valve, is on the left.
– It comprises two primary cusps (hence, "bi" & "cuspid"), anterior and posterior, which ensure unidirectional flow of oxygenated blood from the left atrium to left ventricle. Each primary cusp can be further subdivided into three regions (Anterior 1-3 and Posterior 1-3).
  • Tricuspid valve is on the right.
– It comprises anterior, posterior, and septal leaflets, which ensure unidirectional flow of deoxygenated blood from the right atrium to right ventricle.
Illustrations:
Photos: https://sites.google.com/a/umich.edu/bluelink/resources/bluelinks/unlabeled-heart-images

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