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How does the mitral valve control blood flow on the left side of the heart?
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Circulatory system
Human circulatory system.
The mitral valve, also known as the bicuspid valve, is a critical component of the circulatory system that ensures unidirectional blood flow from the left atrium to the left ventricle.12
Its function is controlled through the following mechanisms:
- Structure: The valve consists of two strong, thick flaps that are reinforced with dense connective tissue to withstand the high pressure generated by the left ventricle.2
- Opening: As the left atrium contracts, blood is propelled through the valve into the left ventricle.2
- Closing: When the left ventricle contracts, blood is forced backward toward the atrium. This pressure pushes the valve flaps upward until they meet, creating a complete partition that prevents backflow.2
- Support: To prevent the flaps from billowing or opening into the atrium under high pressure, they are restrained by chordae tendineae—tendinous cords connected to the papillary muscles within the ventricle.32
If the valve fails to close adequately, it results in mitral insufficiency, allowing blood to leak back into the atrium.3