What is the function of the tricuspid valve?

• A. To regulate flow from the left atrium to the left ventricle.
• B. To prevent backflow of blood from the right ventricle to the right atrium.
• C. To prevent backflow of blood from the pulmonary artery to the right ventricle.
• D. To regulate blood flow from the right atrium into the right ventricle.

Answer: (B)

The main idea is unidirectional flow between the right atrium and right ventricle. The tricuspid valve sits between these chambers and opens to let blood move from the right atrium into the right ventricle during filling. It then closes as the ventricle contracts to prevent blood from flowing backward into the atrium. This one-way function is its primary role in the heart’s rhythm and flow.

To put it in context, the left-sided counterpart (the mitral valve) serves the same purpose between the left atrium and left ventricle, while the pulmonary valve prevents backflow from the pulmonary artery into the right ventricle. Saying it simply regulates flow from the right atrium into the right ventricle is true in a sense, but the most critical function is preventing backflow from the ventricle to the atrium during systole.