The opening between the right atrium and the right ventricle is guarded by the valve named:

• A. Bicuspid valve
• B. Tricuspid valve
• C. Mitral valve
• D. Semilunar valve

The opening between the right atrium and the right ventricle is protected by the tricuspid valve. This valve ensures that blood flows in the correct direction, preventing backflow into the atrium when the ventricle contracts.

Understanding the Heart Valves

Here’s a brief overview of the options provided:

• Bicuspid valve: Also known as the mitral valve, it is located between the left atrium and left ventricle.
• Tricuspid valve: This is the correct answer, situated between the right atrium and right ventricle.
• Mitral valve: Another name for the bicuspid valve, found on the left side of the heart.
• Semilunar valve: These valves are located at the exits of the ventricles, controlling blood flow into the pulmonary artery and aorta.

In summary, the tricuspid valve plays a crucial role in the heart's function by managing blood flow between the right atrium and ventricle.