QS Study

Mitral valve is the valve lies between the left atrium and left ventricle. It is also known as the bicuspid valve. This is one of the heart’s four valves that help avert blood from flowing backward as it moves through the heart.


It has two cusps:

  1. The anterior cusp &
  2. The posterior cusp.

Formation – It is formed by reduplication of the endocardium. It is located in the left side of the heart, between the left atrium and left ventricle. Oxygen-rich blood flows into the left atrium from the pulmonary veins.

The shape of cusp – Triangular.


The bases of the cusps are attached to fibrous tissue and apices to the papillary muscle by chordae tendineae.

Mitral Valve 1

Fig: Mitral Valve

Blood supply

a) Basal 1/3 of the cusp: By branches of the coronary artery.

b) Central 2/3 of the cusp: By directly from the blood in the cavity of the heart.


  1. It regulates blood flow from left atrium to left ventricle.
  2. It prevents regurgitation of ventricular blood.

The main problems that affect the mitral valve are:

  • mitral prolapse – the valve becomes too floppy
  • mitral regurgitation – the valve leaks and blood flows the wrong way
  • mitral stenosis – the valve doesn’t open as wide as it should.
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