The structure that lies between the right atrium and right ventricle is the what?

• A. Tricuspid valve (right AV valve)
• B. Mitral valve
• C. Pulmonary valve
• D. Aortic valve

Answer: (A)

The structure between the right atrium and the right ventricle is the tricuspid valve, the right atrioventricular valve. It opens to allow blood to flow from the right atrium into the right ventricle and closes during ventricular contraction to prevent backflow into the atrium. The tricuspid valve typically has three cusps and is connected by chordae tendineae to papillary muscles, which help prevent valve prolapse when the ventricle contracts.

In contrast, the mitral valve sits between the left atrium and left ventricle; the pulmonary valve is at the outflow from the right ventricle to the pulmonary artery; and the aortic valve is at the outflow from the left ventricle to the aorta.