What causes the mitral valve to open?

What causes the mitral valve to open?

• A. The pressure of blood returning from the body opens the valve.
• B. The weakening of the heart muscles allows for the opening.
• C. The pressure in the aorta is greater than in the left ventricle.
• D. The pressure in the vena cava is greater than in the left ventricle.

Answer: (C)

Opening of the mitral valve is driven by the pressure gradient between the left atrium and the left ventricle. When the heart is relaxed (diastole), the left ventricle’s pressure falls below the left atrial pressure, so blood flows from the atrium into the ventricle through the mitral valve. The aorta’s pressure being higher than the left ventricle’s is what governs the opening of the aortic valve, not the mitral valve. So the mitral valve opens because the left atrial pressure exceeds the left ventricular pressure, enabling ventricular filling.

Opening of the mitral valve is driven by the pressure gradient between the left atrium and the left ventricle. When the heart is relaxed (diastole), the left ventricle’s pressure falls below the left atrial pressure, so blood flows from the atrium into the ventricle through the mitral valve. The aorta’s pressure being higher than the left ventricle’s is what governs the opening of the aortic valve, not the mitral valve. So the mitral valve opens because the left atrial pressure exceeds the left ventricular pressure, enabling ventricular filling.