Federal employees are compensated according to government-regulated pay scales. More than 70 percent of federal employees are paid according to the most common pay scale, the General Schedule (GS) , but there are a variety of alternative pay schedules as well.
Four heart valves control the flow of blood through the heart. They act as one-way doors, opening to let blood exit or enter a chamber, then closing to keep blood from flowing backward. 1  The tricuspid valve controls blood flow from the right atrium to the right ventricle.
There are 4 valves in the heart: tricuspid, pulmonary, mitral, and aortic. In the United States, surgeons perform about 106,000 heart valve operations each year. Nearly all of these operations are done to repair or replace the mitral or aortic valves. These valves are on the left side of the heart, which works harder than the right. They control the flow of oxygen-rich blood from the lungs to the rest of the body. See also on this site: Valve Disease.