Practice question from Anatomy & Physiology
The cardiac cycle phase where all valves are closed and ventricular pressure is rising is called __, while the phase where all valves are closed and pressure is falling is __.
Answer
["isovolumetric contraction","isovolumetric relaxation"]
Explanation
During isovolumetric contraction, the ventricles contract but pressure hasn't yet exceeded aortic/pulmonary pressure, so semilunar valves remain closed while AV valves are already closed. During isovolumetric relaxation, ventricles relax but pressure is still higher than atrial pressure. Both phases have constant volume with no blood flow.