CVS Practice Test

Do the valves of the heart open and close actively or passively?

1. Active

2. Passive

3. Both active and passive

4. Neither active nor passive

The correct answer is: Passive

The correct answer is that the valves of the heart open and close passively. This mechanism is primarily driven by pressure changes within the heart chambers during the cardiac cycle. When the pressure in one chamber exceeds the pressure in the adjacent chamber, the valves open to allow blood to flow through. Conversely, when the pressure in the adjacent chamber becomes higher, the valves close to prevent backflow. This passive function contrasts with active processes that would involve energy expenditure by the heart muscle. Valves do not have muscle tissue and therefore do not contract; instead, they rely on the flow of blood and the pressure gradients created by the heart's pumping actions. This is essential for maintaining the unidirectional flow of blood through the heart and into the vessels.