ANATOMY & PHYSIOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site mitral valve Mitral valve Credit: UCLA Surgery A valve in the heart of mammals and birds situated between the left atrium and the left ventricle. When the left ventricle contracts, forcing blood into the aorta, the mitral valve closes the opening to the left attrium thereby preventing blood from flowing back and so reducing the efficiency of the pumping action. The valve reopens to allow blood to flow from the atrium to the ventricle. The mitral (or bicuspid) valve is the only valve to have two flaps or leaflets; the other three valves in the heart all have three leaflets to close off the inlet and outlet apertures. Mitral valve prolapse is a condition in which the mitral valve does not function properly. Related entry    • heart valve disease Related category    • ANATOMY AND PHYSIOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP