Left atrioventricular orifice

The Left Atrioventricular Orifice (also known as the Mitral Orifice or Bicuspid Orifice) is a vital component of the human heart. It is the opening that allows blood to flow from the left atrium to the left ventricle.

Diagram of the human heart, with the Left Atrioventricular Orifice labeled

Structure

The Left Atrioventricular Orifice is guarded by the mitral valve, which prevents the backflow of blood into the left atrium when the left ventricle contracts. The orifice is approximately 4 to 6 cm in diameter, but its size can vary depending on the individual's heart size and health condition.

Function

The primary function of the Left Atrioventricular Orifice is to facilitate the flow of oxygenated blood from the left atrium to the left ventricle. This is a crucial step in the cardiac cycle, as the left ventricle then pumps this blood to the rest of the body via the aorta.

Clinical Significance

Abnormalities or diseases affecting the Left Atrioventricular Orifice can lead to serious health conditions. For instance, mitral stenosis is a condition where the orifice becomes narrow, restricting blood flow. Conversely, mitral regurgitation is a condition where the mitral valve does not close properly, leading to the backflow of blood.

See Also

• Heart
• Mitral valve
• Cardiac cycle