All the heart valves are open during which stage of cardiac cycle __________________? A. Systolic ejection B. Isovolumetric relaxation C. Isovolumetric contractionD. None of the above

Cardiac output is not affected by __________________? A. Heart rate B. Peripheral resistanceC. Systolic blood pressure D. Venous return

Stroke output of each ventricle in normal adult is_____________? A. 30 ml B. 130 mlC. 70 ml D. 5 liters

Normally, the rate of the heart beat in a human is determined by _________________? A. The bundle of His B. All cardiac muscleC. The sinoatrial node D. The cervical ganglion

The first heart sound is produced by the_____________? A. Closure of the aortic and pulmonary valves B. Opening of the aortic and pulmonary valvesC. Closure of the mitral and tricuspid valves D. Opening of the mitral and tricuspid valves