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.
Once the left ventricle has emptied, the aortic valve closes to keep the blood that has just been pumped out from re-entering the heart. The valves of the heart open and close in a sequential fashion and are critical to normal heart function. Various conditions can affect the function of the heart valves.