Ventricular pressure is rising rapidly while ventricular volume stays constant, just before the aortic valve opens. Which phase of the cardiac cycle is this?
Answer and explanation
Correct answer: D. Isovolumetric contraction
- Step 1: Both the mitral and aortic valves are closed, so no blood enters or leaves the ventricle and its volume is constant. Step 2. Pressure climbs until it exceeds aortic pressure. Answer: isovolumetric contraction. Why not the others: in ejection the volume falls; in isovolumetric relaxation the volume is also constant but pressure is falling; in filling the volume rises.
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