What is the name of the valve between the left atrium and left ventricle?

The valve between the left atrium and left ventricle is the mitral valve. It is also called the bicuspid valve or the left atrioventricular valve.

The mitral valve opens during ventricular diastole, allowing oxygen-rich blood returning from the lungs to flow from the left atrium into the left ventricle. It closes when the ventricle contracts, preventing blood from flowing backward into the atrium as the heart pumps blood into the aorta.

The valve has two leaflets, or cusps, supported by chordae tendineae and papillary muscles. These structures help the leaflets close securely under pressure. Its name comes from mitre, a ceremonial bishop’s headdress whose shape was thought to resemble the valve.

The most common mix-up is with the tricuspid valve, which lies between the right atrium and right ventricle. Disorders of the mitral valve include mitral stenosis, in which it narrows, and mitral regurgitation, in which it leaks.