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.
The tricuspid and mitral valves lie between the atria and ventricles. The aortic and pulmonic valves lie between the ventricles and the major blood vessels leaving the heart. The heart valves work the same way as one-way valves in the plumbing of your home. They prevent blood from flowing in the wrong direction.