1530s, a running (usually at full speed), a course (especially of the sun, etc., across the sky), from Middle French carriere road, racecourse (16c.), from Old ProvenÃ§al or Italian carriera, from Vulgar Latin *(via) cararia carriage (road), track for wheeled vehicles, from Latin carrus chariot (see car).
Noun. 1. tricuspid valve-valve with three cusps; situated between the right atrium and the right ventricle; allows blood to pass from atrium to ventricle and closes to prevent backflow when the ventricle contracts. right atrioventricular valve.
Heart valves separate the atria from the ventricles, or the ventricles from a blood vessel. Heart valves are situated around the fibrous rings of the cardiac skeleton. The valves incorporate leaflets or cusps, which are pushed open to allow blood flow and which then close together to seal and prevent backflow. heart valve normally allows blood to flow in only one direction through the heart. The four valves commonly represented in a mammalian heart determine the pathway of blood flow through the heart. A heart valve opens or closes incumbent on differential blood pressure on each side. The four main valves in the heart are: