Of the following, which valve is more resistant to regurgitation?

The aortic valve is more resistant to regurgitation compared to the other valves due to its structural design and the distinct hemodynamic forces it encounters. This valve is a semilunar valve located between the left ventricle and the aorta. Its shape and the mechanism of closure are optimized to handle the high pressures generated during ventricular contraction, sealing tightly to prevent backflow of blood into the left ventricle during diastole.

Additionally, the aortic valve has a critical role in maintaining systemic blood flow and pressure, so its ability to prevent regurgitation is paramount for effective cardiovascular function. The valve leaflets are designed to ensure a robust closure, minimizing the likelihood of any reverse flow, which is especially important given the considerable forces at work in the systemic circulation.

In contrast, the other valves, such as the pulmonary, mitral, and tricuspid valves, have different functional requirements and structural characteristics that make them more susceptible to regurgitation under certain conditions. The pulmonary valve, while also a semilunar valve, experiences lower pressures than the aortic valve, and therefore, it doesn't require the same level of resistance to regurgitation. The mitral and tricuspid valves are atrioventricular valves that