Which valve is located between the left atrium and the left ventricle?

• A. Tricuspid valve
• B. Pulmonary valve
• C. Aortic valve
• D. Mitral valve

Answer: (D)

The valve between the left atrium and the left ventricle is the mitral valve, also known as the bicuspid valve. It has two cusps and opens to allow oxygen-rich blood to flow from the left atrium into the left ventricle during heart relaxation (diastole). When the ventricle contracts (systole) the mitral valve closes to prevent blood from flowing back into the left atrium as blood is pushed through the aortic valve to the body. This contrasts with the tricuspid valve, which lies between the right atrium and right ventricle; the pulmonary valve, at the exit of the right ventricle to the pulmonary artery; and the aortic valve, at the exit of the left ventricle to the aorta.