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 four main valves in the heart are: 1  The two atrioventricular (AV) valves, the mitral valve (bicuspid valve), and the tricuspid valve, which are between the upper chambers (atria) and the lower chambers (ventricles). 2  The two semilunar (SL) valves, the aortic valve and the pulmonary valve, which are in the arteries leaving the heart. The mitral valve and the aortic valve are in the left heart; the tricuspid valve and the pulmonary valve are in the right heart. There are also the coronary sinus and the inferior vena cava valves.