What is the structure of the tricuspid valve?

• A. Three flaps (cusps) of tissue.
• B. Two flaps (cusps) of tissue.
• C. One flap (cusp) of tissue.
• D. Four flaps (cusps) of tissue.

Answer: (A)

The tricuspid valve is the right-sided atrioventricular valve and has three leaflets, or cusps. These cusps—anterior, posterior, and septal—are folds of endocardial tissue reinforced by fibrous tissue, anchored by chordae tendineae to papillary muscles. This setup allows the valve to open to let blood move from the right atrium into the right ventricle, and then snap shut during ventricular contraction to prevent backflow into the atrium. The three-cusp design is why it’s described as tricuspid. In contrast, a valve with two cusps is the mitral valve, one cusp is not typical, and four cusps would be a rare quadricuspid variant.