AV vs. Semilunar Valves: Key Differences & Heart Function Explained
Atrioventricular (AV) valves are the tricuspid and mitral gates between atria and ventricles; semilunar valves are the aortic and pulmonary exits between ventricles and arteries.
Students swap the names because both sets open and shut in rhythm, yet one stops backflow into atria, the other into arteries. Mixing them leads to misreading ECGs and heart-murmur charts.
Key Differences
AV valves have chordae tendineae and operate under lower pressure; semilunar valves are pocket-shaped, handle high arterial pressure, and have no cords.
Which One Should You Choose?
In diagnostics, choose AV when studying preload and regurgitation; pick semilunar when assessing afterload and stenosis.
Do AV valves ever close at the same time as semilunar valves?
No—AV valves shut at systole’s start, semilunar valves open milliseconds later.
Can one be faulty while the other stays healthy?
Yes; mitral prolapse can coexist with a normal aortic valve.